of Spencer (used with glycerine for very oblique, and with water for axial illumination) "were manifestly superior, not only showing the markings of Amphipleura pellucida blacker and finer, but standing better the test of deepest eye-pieces without flinching."

Botrydium granulatum.- The Botrydium granulatum, which inhabits the clayey mud on the borders of ponds, is composed of an aerial part, globular, green, and the size of a pin's head, and of a subterranean rhizoid part, which is only an attenuated prolongation, ramified by dichotomy of the globular aerial cell. This latter alone contains chlorophyll. Transferred to a drop of water, it gives birth to numerous asexual zoospores, furnished at their extremity with a single vibratile cilium, and capable of immediate germination.

But, on the contrary, when the atmosphere is dry, this sporangium shrivels up and empties itself; its protoplasm passes into the root-like apparatus, where it collects into little masses, each of which is surrounded by a membrane, and it is then in these cells of accidental formation (subterranean zoosporangia) that the zoospores are formed. In other cases, there appears on a point of the root-like system a vesicle which rises above the surface of the ground, and which is capable of living all the year, and even of undergoing a period of desiccation, before producing these zoospores. This vesicle (hypnosporangium) is rounded; it is this to which has been given the name of Botrydium Wallrothii.

Under other influences, and chiefly under that of direct exposure to the sun, the contents of the aerial organ of Botrydium may break up into a certain number of cells, furnished with membranes,* whose colour, green at first, may be transformed later on into a fine red. These cells, when liberated, give birth to numerous biciliated zoospores; these last can reproduce the individual only after a copulation similar to that which M. Pringsheim has described in the Pandorina Morum, and after being fused in pairs into isospores.†

The Life-History of Filaria Bancrofti.-Dr. T. Spencer Cobbold, F.R.S., devotes a paper to this organism, which he terms "one of the most remarkable parasites that has ever engaged the attention of helminthologists." The paper firsts shows the steps by which we have acquired our present knowledge, through the discoveries of Wucherer, Lewis, Bancroft, Manson, Sonsino, the author, and others. What that knowledge actually expresses when summarized in the lowest possible number of convenient terms is stated in the following six "propositions":

1. Filaria Bancrofti is the sexually mature state of certain microscopic worms hitherto obtained either directly or indirectly from human blood.

2. The minute hæmatozoa in question, hitherto described as Wucherer's Filaria, Filaria sanguinis hominis, Trichina cystica, Filaria

*These are the cells which have been described under the name of Protococcus coccoma, P. palustris, P. botrydioides.

+ Review of MM. Rostafinsky and Woronin's paper (published in Leipzig), 'Bull. de la Soc. Botanique de France,' vol. xxv. p. 14.

dermathemica, and so forth, are frequently associated with the presence of certain more or less well-marked diseases of warm climates.

3. The diseases referred to include chyluria, intertropical endemic hæmaturia, varix elephantiasis, lymph-scrotum, and lymphoid affections generally, a growth called Helminthoma elastica, a cutaneous disorder called craw craw, and also not improbably leprosy itself.

4. It is extremely probable that a large proportion, or at least that certain varieties of these affections are due to morbid changes exclusively resulting from the presence of Filaria Bancrofti or its progeny within the human body.

5. It is certain that the microscopic hæmatozoa may be readily transferred to the stomach of the blood-sucking insects, and it has been further demonstrated that the digestive organs of the mosquito form a suitable territory for the further growth and metamorphosis of the larval Filaria.

6. The character of the changes undergone by the microscopic Filaria and the ultimate form assumed by the larva whilst still within the body of the intermediate host (Culex mosquito), are amply sufficient to establish the genetic relationship as between the embryonal Filaria sanguinis hominis, the stomachal Filaria of the mosquito, and the sexually mature Filaria Bancrofti."

Dealing with the practical consequences which may be expected to flow from a fuller recognition of the importance of this Filaria, the author points out that a consideration of the highest value in relation to epidemiology generally, and more especially in regard to the practical question as to the best methods of stamping out parasitic plagues, is that which refers to the life-history of the entozoon itself. It must be obvious that in all cases where the intermediate host can be captured and destroyed, the life cycle of the parasite can be broken or interrupted; and if thus broken there is an end to the further propagation of the species. The knowledge that we have acquired by experimental research in this direction has already enabled us to set a limit upon the prevalence of certain well-known disorders, such as trichinosis, cestode tuberculosis, and so forth. In the case of epizootics, however, which are not merely dependent upon minute entozoa, but which are also, in the way that we have seen, indirectly due to the action of intermediary hosts that cannot be readily captured or destroyed, our power of arresting the disease is comparatively limited. In the case of Filaria Bancrofti it is probably not necessary either that a dead or living mosquito should be swallowed to ensure infection; but it is necessary that the parasitic larvæ should have dwelt within the mosquito in order to arrive at the highest stage of larval growth prior to their re-entrance within the human territory. Undoubtedly the larvae of Filaria Bancrofti are swallowed with potable waters. The perfect filtration of these waters before use would certainly che k, and in course of time would probably cause the total extinction of several of the many virulent diseases that now afflict the inhabitants of warm climates.*

* Journal of the Linnean Society' (Zool.), vol. xiv. p. 356. VOL. I.

2 D

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Oleomargarine.-A controversy has been recently raging at New York in regard to the qualities of this substance, between Mr. John Michels and some correspondents of the New York Times.' In an article in the American Journal of Microscopy,' for October, Mr. Michels writes:

"Having observed paragraphs in various medical and scientific journals, stating that oleomargarine could not be distinguished by the microscope from butter, and suggesting various chemical methods to meet the difficulty, I was prompted to purchase samples of these substances, and make a careful microscopical examination of them.

The result of my examination was very decisive, and just what I expected; namely, that the oleomargarine was loaded with free stellate or feathery crystals, and that the butter presented the uniform appearance of fat-globules so often described in handbooks, and perfectly free from any crystalline forms except those of chloride of sodium or common salt.

I examined a large number of samples under different temperatures, and under a variety of conditions, but the results here shown * are from two samples examined just as they were purchased, pressed out to a fine film in the usual manner, under a thin cover, and examined with a four-tenth objective by Beck.

During some months I always found the same results, but discovered that by a trick and by manipulating the samples, the butter could be made to show a field full of crystals, and the oleomargarine free from them; but examine true samples of either in their normal condition, and the results I have shown will always be observed.

As I have stated, my examination of oleomargarine extended over some months, during which period I invariably found that each sample contained cells of a very suspicious character, with fragments of tissue and muscle. This led me to investigate the process of manufacture, and I then found that during the whole process from first to last, the animal fat, &c., of which this substance is made, is never subjected to a higher temperature than 120° F.

It at once occurred to me, that taking into account the wellknown thermal death-point of certain organisms frequently found in animals, which, although diseased, are regarded by dealers as fit for food, such a temperature of 120° F. was totally insufficient to destroy the germs of even the adult individuals of such forms of life.

Again, the original French patent states that the stomachs of two pigs or sheep should be chopped up with a certain amount of fat, on account of the pepsine there contained, and I found that this practice was in use in the New York oleomargarine manufactories. For these reasons I conclude that oleomargarine thus manufactured is not a safe or wholesome article of food, and I assert that, however disguised it may be in appearance, oleomargarine as offered for sale, is nothing but raw fat, liquefied, scented, coloured and flavoured to give it a spurious appearance of butter, and that those who use it run the risk of trichinæ, from the stomachs of pigs chopped up with the fat, and Two woodcuts-one showing the usual appearance of fat-globules, the other stellate or feathery crystals.

NOTES AND MEMORANDA.

that infection from certain contagious diseases, which are common to man and the domestic animals, might follow."

The opposition which these views encountered is then referred to, particularly that of Professor J. W. S. Arnold, of the University of New York, who stated that he had examined with the microscope the two substances, and found their "optical appearance alike," which is accounted for, according to Mr. Michels, by the Professor having allowed the oleomargarine manufactory to prepare the specimen examined.

A letter from the Rev. W. H. Dallinger as to a temperature of 120° F. not being permanently injurious even to adult forms of putrefactive organisms is given, and Mr. Michels concludes by referring to "the following independent confirmation, which was published in the 'Scientific American,' giving the result of the appearance of butter and oleomargarine under the microscope, by Mr. Thomas Taylor, Microscopist of the Department of Agriculture at Washington.

Mr. Taylor reports that when pure dairy butter is viewed under the microscope, the forms consist of oil-globules, and the crystals of common salt; when a specimen of oleomargarine was examined in the same manner, the field was speckled over with shiny particles, and it was demonstrated that these glistening particles were crystals of fat. In using a power of 250 diameters, animal tissue is seen more or less all over the field. One specimen of oleomargarine was highly charged with animal tissue and crystals of urate of magnesia, showing the fat prove that used in this case to have been impure, which would seem to the assertions made by the oleomargarine manufacturers as to the perfect purity of the fats used by them, are not altogether correct.

From this it would appear that oleomargarine may be easily known from butter by the aid of the microscope, and that any impurities in the fats of which it may be composed may be readily detected."

Microscopical Slides of Lichens.-The intended issue is announced (by Messrs. Joshua and Holmes) of a series of microscopical slides, illustrating the principal families, genera and sub-genera of lichens, to be followed by a series of specimens of lichens of which no figures have been published. The specimens are to be as typical as can be procured, and will consist of sections of the apothecia, showing all the various parts.

Limits of Microscopic Vision.-Extracts from a letter from Professor Stokes, Sec. R.S., as to Fraunhofer's formula, and one from Mr. J. Mayall, jun., will be found with the discussion on Dr. Pigott's paper, in the Proceedings,' at p. 389.

Pygidium of Insects.-The discussion at the November meeting on this subject will also be found in the 'Proceedings,' at p. 390.

Raphidiophrys pallida.-A note by Professor E. Ray Lankester on this Rhizopod (new to this country) will be found at p. 393.

Barry, A. de: Micro-photographs of Botanical Preparations. Part I. (10 plates.) (Strassburg.)

Berger, Emil: Researches on the Structure of the Brain and the Retina of the Arthropoda. (5 plates.) (Vienna.)

Braithwaite, R., M.D., F.L.S.: The Sphagnacea, or Peat-Mosses of Europe and North America. (With 29 plates.) (London.)

Drysdale, Dr. J.: The Germ Theories of Infectious Diseases. (London.)

Duval, Dr. M.: Précis of Microscopical and Histological Technic. (With 43 woodcuts.) (Paris.)

Exner, Professor S.: Guide to the Microscopic Investigation of Animal Tissues. Second Edition. (With 7 woodcuts.) (Leipzig.)

Eyferth, B.: The Simplest Forms of Life. Systematic Natural History of the Microscopical Inhabitants of Fresh Water. (With 5 plates.) (Brunswick.) Fayel, Ch. My Photographic Microscope. (Caen.)

Foster, Michael, M.D., F.R.S., and F. M. Balfour, M.A.: The Elements of Embryology. Part I. (London.)

Funcke and Thelen: Micro-photograms. (Witten.)

Magnin, A.: The Bacteria.

(Paris.)

Marsh, Dr. S.: Section-Cutting; a Practical Guide to the Preparation and Mounting of Sections for the Microscope. (With 5 woodcuts.) (London.) Mereschkowsky, K. S.: Studies on the Protozoa of Northern Russia. (St. Petersburg.)

Recklinghausen and Meyer: Micro-photographs of Pathological-Anatomical Preparations. Part I. (10 plates.) (Strassburg.)

Stein, Dr. Fr. Ritter von: The Organisation of the Infusoria according to accurate Researches. Part III. The Natural History of the Flagellata. 1st Half. (24 plates.) (Leipzig.)

Strassburger, E.: Fructification and Cell Division. (With 9 plates.) (Jena.) Thuret, G Phycological Studies. Analyses of Marine Algae. Fol. (With 50 plates.) (Paris.)

Tieghem (P. v.): Third Memoir on the Mucorini. (With plates.) (Paris.) White, Dr. R., jun.: Microscopic Organisms in Cochituate Water. (Cambridge, U.S.)

Journals, Transactions, &c :

ANNALS AND MAGAZINE OF NATURAL HISTORY. Vol. II., No. 11 (for November):

Fifth Series,

On the Structure and Affinities of the Genus Catagma. By W. J. Sollas, M.A., F.G.S., &c. (With a plate.)

Miscellaneous.

--

Studies on Fossil Sponges. II. Lithistidæ. By Karl Alfred Zittel. (Continued.) The Nauplius Stage of Prawns. By Fritz Müller and C. Spence Bate.-Amphipoda in Sponges. By the Rev. T. R. R. Stebbing, M.A.On the Oviposition of the Queen Bee and Dzierzon's Theory. By M. J. Pérez. (From Comptes Rendus.')—On the Cause of Buzzing in Insects. By M. Jousset de Bellesme. (From Comptes Rendus.')-On the Ascarides of the Seals and Toothed Whales. By Dr. H. Krabbe. (From Oversigt af Kongl. Danske Vidensk. Selsk. Forhandl.,' i. Aaret, 1878.)

No. 12 (for December):

New Hydroida from Ochotsk, Kamtschatka, and other parts of the North Pacific Ocean. By C. Mereschkowsky. (With 2 plates.)

Studies on Fossil Sponges. II. Lthistide. By Karl Alfred Zittel.