seems to be a sort of mania on the part of many naturalists to propose specific names on the least provocation.

Spongilla fluviatilis is found in very many forms in different localities which, by careful comparison, show such gradual gradations that they are undoubtedly merely varieties of one species. A plate showing the forms of spicules is given.

JOURNAL DE MICROGRAPHIE.

This Journal, edited by Dr. J. Pelletan of Paris, although only in its second year, is undoubtedly one of the most valuable journals published in the special line of microscopy. In plan it is quite different from any other, and the "Review" with which each number opens, from the pen of the editor, is always full of interest.

We briefly abstract from the numbers at hand as follows:

May, 1878.

LYMPHATIC HEARTS.-Prof. Ranvier.-A continuation of a lecture at the College of France. It begins in this number with a study of the nerve of the posterior hearts, and then follow a few words on the lymphatic hearts of serpents.

The last division here given relates to the structure of these organs in Batrachians.

OBSERVATIONS ON THE TERMINATION OF THE MOTOR NERVES IN THE STRIATED MUSCLES OF THE TORPEDO AND THE RAYS, AND ON THE RESEMBLANCE BETWEEN THE ELECTRIC AND MOTOR PLATE OF THE TORPEDO.—Prof. C. V. Ciaccio.—Continuation.

NEW RESEARCHES ON THE INTIMATE STRUCTURE OF THE RETINA IN BIRDS.-Dr. Al. Tafani.—Continued.

STUDY UPON FOREIGN MICROSCOPES.-Dr. Pelletan.-This is one of a series of articles on the subject. A full and good description of Mr. Zentmayer's "Centennial" stand is given. Dr. Pelletan is not sparing in his praise of this specimen of American workmanship.

Following this is quite as long an account of Mr. R. B. Tolles's new large stand, which also receives a due portion of praise.

THE VERNIER APPLIED TO the BoDy-tube of the MICROSCOPE. -L. M. Bawens.-The author states that about ten years ago he applied a vernier to his microscope (Jackson model), for the purpose of measuring the thickness of cover glasses and other work.

June, 1878.

LYMPHATIC HEARTS.-Prof. Ranvier.-Continued.

OBSERVATIONS ON THE TERMINATION OF THE MOTOR NERVES, ETC.-Prof. C. V. Ciaccio.-Continued.

THE MICROSCOPES AT THE PARIS EXPOSITION.-Dr. Pelletan.This is the first of a series of articles, and is a general view of the microscopes of the whole exhibition.

It embraces much that is interesting, and some things are said about the conservative French and German makers which they would do well to think about. We have not room to devote to this subject, but must notice a few points.

The exhibition of microscopes is a very large one, but they are much scattered about among the exhibits" of different nations. Among others on the Continent, were exhibited instruments by Nachet, Verick, Hartnack & Prazmowski, Chevalier, Culot, Mirand, Bardou, Lebrun, Seguy, Jaubert.

Ross & Co. had some splendid stands of large and medium size, some modeled upon the Ross, and others upon the Jackson style. "Among the latter, I remark six models which are copies, pure and simple, of the "Centennial" of Mr. J. Zentmayer; the sub-stage and mirror, connected, revolve about the focal point, and the slow movement acts upon the entire tube." Mr. J. H. Dallmeyer, of London, exhibited some stands on the Ross model, and Mr. Crouch was also represented. The display of Mr. Swift is highly spoken of.

From the United States only four makers are represented, but these are of much importance.

The Bausch & Lomb Company have a full set of their instruments from the large "professional" down, and a series of objectives, from a 2 inch to the immersion.

Mr. Zentmayer only sent a single stand, and this was his “Centennial." Beside this is a box containing "26 magnificent preparations," by Mr. Charles Zentmayer, mostly double stained.

Chas. A. Spencer, and Sons of on exhibition, among which is a examined in future.

Geneva, have a number of objectives

20

duplex immersion. These will be

"S. Plössel, Vienna, *** exhibits no micrscopes; it appears that this is for prudential reasons."

Mr. J. Rosenthal, Vienna, shows some precisely like Hartnack's. There are many other exhibitors, but we must pass them by,—all but the last one. There is a small stand in the Japanese department which might be English, or it might be American, but it has an inscription which, being translated by the polite native exhibitor, who "speaks French better than an Englishman, and English better than a Frenchman," evidently referred to the name of the maker in Tokio.

ON THE GOLD METHOD, AND THE TERMINATION OF THE NERVES IN THE "MUSCLES LISSES' -L. Ranvier.-From Comptes Rendus. CRYPTOGAMIC BOTANY.-Programme of the course of M. Leon Marchand, at l' Ecole Superieur de Pharmacie de Paris.

A NEW FIELD OF STUDY FOR THE MICROSCOPIST.-W. Saville Kent. From the Popular Science Review, April, 1878.-To be continued.

ON THE MEASUREMENT OF THE ANGLES OF MICROSCOPIC CRYS

TALS.-Em. Bertrand.-Comptes Rendus, December 17th, 1877.

This

is really an ingenious arrangement, and appears to be quite practicable and accurate. Want of space only prevents us from translating it entire.

In the eye-piece is placed a cylinder of glass of higher refractive power than balsam. This cylinder is split lengthwise, the surfaces

polished and again cemented together with balsam.

With direct illumination, the field is illuminated equally and a line crosses it. When a crystal, the surface of which is large enough to change the direction of the rays of light, is placed upon the stage, these rays suffer total reflection in the eye-piece cylinder, owing to the film of balsam.

One can readily understand what the effect would be in this case, and how the instrument is used. It makes a revolving concentric stage unnecessary.

TRANSPORTING LIVING SPECIMENS FOR THE MICROSCOPE.-Dr. Pelletan. A notice of the enterprise of Mr. T. Bolton, of Birmingham, who, being an industrious collector of objects, has for some time been selling them, and sending them by mail in little glass tubes. A long list of objects, which he supplies, is given. This is certainly of great value to microscopists, but in this country we cannot enjoy such benefits.

NEW MODEL MICROSCOPE, OF MR. R. B. TOLLES, BOSTON.-Geo. E. Blackham, M. D., Dunkirk, N. Y.-A detailed description of a stand recently made for the author.

THE "TRANSPORTER" OF PROF. MONNIER.-This is a mounting instrument for placing the cover glass in position. Its use is described.

July, 1878.

LYMPHATIC HEARTS.-Prof. Ranvier.-Continued.

OBSERVATIONS ON THE TERMINATION OF MOTOR NERVES IN THE STRIATED MUSCLES OF THE Torpedo FISH, ETC.-Continued.

PRELIMINARY NOTE ON THE DEVELOPMENT OF BLOOD AND VESSELS.-Drs. V. Brigidi and Al. Tafani.

These studies, which appear to have been carefully conducted, were made in great part upon the embryo of Cyprinus auratus while living, and this subject the authors consider peculiarly adapted to the work. The germ, freed from the testaceous membrane, may be placed in a cell with a drop of water, covered, and can be long examined without the use of an anæsthetic. We can barely indicate the results of these studies. It is affirmed, and will be more fully shown, in a forthcoming memoir, entitled the " Embryology of Cyprinus auratus," that the blood and vessels have their origin in a special “feuillet" which appears about the second day after fecundation. This the authors designate as the "vascular feuillet," and they thus verify the observations of former students.

They feel fully justified in saying that the white corpuscles are formed

at a later period than the red. They reject the doctrine that the heart and vessels are formed before the blood, but they appear contemporaneously. To be continued in the next number.

MICROSCOPY AT THE UNIVERSAL EXPOSITION OF PARIS.-Dr.

Pelletan.

NOTE ON THE APPLICATION OF AMMONIUM PICROCARMINATE TO THE ANATOMICAL STUDY OF INTESTINAL WORMS.-Dr. G. Duchamp. -Owing to the difficulty in making out the structure of these worms after death, which produces almost immediate alteration, this coloring solution was tried with apparently perfect success, and the preparations can be preserved. The worm is merely placed, while living, in the ordinary picrocarminate for about thirty minutes.

CRYPTOGAMIC BOTANY.-Continued.

ON THE GUM DISEASE OF CITRON TREES, (Fusisporium limoni, Briosi).-C. Briosi.—This is only an introduction to what promises to be an interesting account of the author's investigations. A review of the history of the disease is given, and the questions he proposed to solve in beginning the work himself.

RESEARCHES ON THE COMPARATIVE ANATOMY AND THE DevelopMENT OF TISSUES IN THE STEM OF MONOCOTYLEDONS.-E. Dubreuil. -This is a review of a thesis by Dr. A. Guillaud, and it is of such a nature that we must give it some space here.

The thesis is divided into two parts. The first is purely anatomical. Plants are divided into six distinct types, and by further study this number may be increased. Each of these types shows some peculiarity of organization and they do not pass gradually into each other.

Type I. This is characterized by the absence of special tissues; the fundamental cortical tissue passes without the least modification into the medullary parenchyma. Example, Polygonatum vulgare.

Type II. This type is distinguished by the presence of a more or less complex band of special tissues, developed about the external ring of bundles. This band constitutes an intermediate zone between the pith and bark, isolating the parenchyma of the two regions. Examples, Iris florentina, L., Chamoedorea elatior, Mart. Acorus calamus, L., Scirpus lacustris, L. These examples constitute different sub-types which may be distinguished.

Type III. In this type the rhizomes are long and slender. The bundles, less numerous than usual, do not describe a central curvature, are not decussate, and are ranged in a circle or in a definite ring as in ordinary Dicotyledons. Example, Luzula campestris, D. C.

Type IV. This, like the last, is founded on the arrangement of the bundles, which form two groups isolated in the inter-nodes and only reuniting as they enter the leaves; the one includes those in which the bundles, curved towards the centre, occupy the interior of the pith; the other, those with straight bundles which form the ordinary circle and the limit of the bark. Example, Tradescantia.

Type V. This is characterized by the formation of a secondary mass of prosenchymatous tissue, hard, forming from one end to the other of the rhizome, of Triglochin maritimum, for example, a solid triangle of pseudo liber-like tissue; and similarly situated in other plants, as Schoenus nigricans, Marsilea and Posidonia Caulini.

Type VI. In this type the bundles in the branches, and also sometimes the rhizomes are provided with two tissues isolated and distinct. One develops behind and near the air vessels, the other in front. A. times there are many liber fibers as in certain Dioscorea. Example, Tamus communis, L.

In these two latter types there is usually an intermediate zone more or less developed.

The second part is a long exposition of the general anatomy of these types of monocotyledons, of which not sufficient is given to furnish material for a good résumé.

ON THE APPLICATION OF THE MICROSCOPE TO THE STUDY OF MINERALOGY.-Em. Bertrand.-This paper first describes how the apparatus for measuring the angles of crystals, aleady noticed on page 76, can be practically applied to the microscope, and also an improvement upon its former construction. Then follow a few words about the study of the optical properties of double refracting crystals by the microscope. To determine the position of the axis of a crystal, four sectors of quartz are mounted in the eye-piece with optical rotation alternately to the right and left, and these, by their color, indicate the position of the prisms. This has already been described in another journal. An arrangement is also described for using converging light with the polariscope.

A NEW FIELD OF STUDY FOR THE MICROSCOPIST.-Continued.

August 1878.

LYMPHATIC HEARTS.-Continued.

OBSERVATIONS ON THE TERMINATION OF MOTOR NERVES, ETC.Concluded.

PRELIMINARY NOTE ON THE DEVELOPMENT OF BLOOD AND VESSELS.-Continued.

The blood when it first appears is in vessels in no wise different in structure from those of the adult; the blood of the embryo and of the perfect animal has precisely the same properties. Authors consider that the first rudiments of the heart or vessels cannot be distinguished until they present endothelial elements, and that a collection of elements of indefinite character, having no other importance than that they occupy the position of the heart, should not be regarded as a stage in its development.

In this paper the development of the heart is described until the contraction begins and circulation is established.