Mechanical fingers," by C. M. Vorce, of Cleveland. In this paper the mechanical finger was spoken of as a kind of stage forceps adapted to objects too small and fragile for ordinary forceps, and as an important accessory for the microscope, even as a means of study of minute forms and to those who do not wish to mount objects. Those forms of finger were described which are attached to the objective or to the movable stage, and the home manufacture of them recommended as easy and effective Their efficiency is greater in proportion to the greater number of movements of the stage and sub-stage. The apparatus should be furnished with a variety of points for different kinds of work. varying from a fine mouse-whisker to a split point of whalebone or quill.

Microscopical study of the ashes of leaves," by Dr. R. H. Ward, of Troy, describes the method by which leaf ashes may be prepared so as to preserve much of the structure of the leaf. The books speak of the siliceous residue of the leaves of the grasses, but many other leaves are equally available. Leaves of trees are generally used with more success than those of herbs, and they should be gathered late in the summer. A piece of dry leaf is laid on a strip of platinum foil or thin mica, covered with mica or a cover-glass to prevent curling up, and carefully heated over an alcohol lamp or Bunsen burner until the organic matter is slowly burned out and the mineral matter, or ash, remains undisturbed. This is then dropped on to a slide, wet with turpentine, and very carefully mounted in soft balsam. If slightly crushed in mounting, or containing a trace of carbon at some point, the value of the object is often increased. These preparations can be made with great ease and rapidity, and show the construction of the parenchyma, veins, epidermis, stomates and hairs with great beauty and distinctness. In this way was prepared a slide of leaf ashes which was recently sent througà the circuits of the Postal Club and which excited an unexpected amount of interest and correspondence.

"Classification of algæ," by Rev. A. B. Hervey, described the systematic arrangement of sea weeds by means of their peculiarties of reproduction, and showed how completely our knowledge of the subject is due to the microscope. The writer urged the more frequent preparation, for use and for exchange, of series of slides illustrating typical species in groups studied by specialists in natural history. To be Continued.)

MICROSCOPICAL DIRECTORY. The fullest list of American microscopists yet published will be found in the "Naturalists' Directory for 1878," published by S. E. Cassino, Salem, Mass.

EXCHANGES.--Lake Michigan diatoms mounted or raw material, also diatoms of Northern Illinois, for good slides or material. B. W. Thomas, 132 La Salle street, Chicago, Ill.

SCIENTIFIC NEWS.

We have received a specimen of the first number of the Zoologischer Anzeiger, edited by Prof. J. V. Carus. From twentyfive to twenty-six sheets, of sixteen pages each, will appear each year, a sheet about once a fortnight, we suppose. The literature

in all departments except descriptive zoology is fully given by title; digests or abstracts of important works are given, C. O. Whitman's embryology of Clepsine being thus noticed. The Anzeiger will also contain short notices, zoological, zoötomical, faunistic, phænological and biological, with laboratory notes as to improved methods of working, information regarding museums, private collections and personal notices. The plan of this zoological index is excellent, and will undoubtedly prove a most convenient medium for advanced zoölogists.

Arrivals at the Philadelphia Zoological Garden: 1 gray squirrel (Sciurus carolinensis); 3 beavers (Castor fiber), born in the garden; I diamond rattlesnake (Crotalus adamanteus); I ground rattlesnake (Candisona miliaria); I whip snake (Bascanion flagelliforme); 1 black snake (Bascanion constrictor); I spreading adder (Heterodon platyrhinos); 2 brown-throated parrakeets (Conurus æruginosus); I snake (Coluber obsoletus, confinis); 3 bald eagles (Halietus leucocephalus); 1 king snake (Ophibolus getulus); I woodchuck (Arctomys monax); I robin (Turdus migratorius); I snake (Coluber vulpinus); I rufous rat kangaroo (Hypsiprymnus rufuscens), born in the garden; 11 lizards (Sceloporus undulatus); I red fox (Vulpes fulvus).—Arthur E. Brown, Supt. of Garden, Sept. 1, 1878.

The Commissioner of Agriculture has appointed Mr. A. R. Grote, of Buffalo, N. Y., Wm. J. Jones, of Virginia Point, near Galveston, Texas, E. H. Anderson, of Kirkwood, Miss., and Prof. Comstock, of Cornell University, observers, under the control of the entomologist of the Department, to make investigations and study the action of the cotton worm during the present season.

Prof. Carl Stål, Director of the Department of Entomology of the Royal Museum at Stockholm, died June 13, 1878, aged forty-five years. He was a voluminous author, publishing monographs of different groups of Coleoptera, Hemiptera and Orthoptera.

— Dr. John H. Packard reports in the Medical and Surgical Reporter (Phil., Aug. 3, p. 100) that a child six years of age blew from its nostrils a specimen of Geophilus, a long, slender, small, centipede-like myriopod.

- Herr A. Reipert, of Bensheim, Burgstrasse, Grossl. Hessen, is desirous of corresponding with American entomologists with a view to exchanging European for American insects.

PROCEEDINGS OF SCIENTIFIC SOCIETIES.

THE AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE met at St. Louis, August 21st, the session lasting a week. The president was Prof. O. C. Marsh, Prof. Simon Newcomb being the retiring president. Reports of the eclipse observers seemed to have overshadowed the papers read in the section of geology and biology. The attendance and number of papers read was smaller than the preceding year. An excursion to Colorado took place at the close of the meeting.

THE BRITISH ASSOCIATION met at Dublin, August 14th, under the presidency of Dr. Spottiswoode, the number of members present being 2,577. The addresses of Mr. Evans on Geology, of Prof. Flower on Vertebrate Zoölogy, and of Mr. Romanes on Animal Intelligence were of especial interest, as well as the address of Sir Wyville Thompson on Recent Progress in Ocean Geography.

THE MEETING OF GERMAN NATURALISTS AND PHYSICIANS Was held at Cassel, September 11-18, the president being Dr. B. Stilling.

THE FRENCH ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE was presided over by M. E. Fremy. Prof. Marey delivered a lecture on Graphic Researches relative to Animal Motors, and papers were read by M. Alix on the Myology of Mammals, by Prof. A. Gaudry on the Evolution of Primitive Mammals, and M. A. F. Nogues on Method in Geology and on the Climatology of Geological Times.

-:0:

SCIENTIFIC SERIALS.1

THE AMERICAN JOURNAL OF SCIENCE.-September. On the animal of Millepora alcicornis, by W. N. Rice. Forest geography and archæology, by A. Gray (continued from p. 94). Notice of some recent additions to the marine fauna of the eastern coast of North America, by A. E. Verrill. The Waverly Group in Central Ohio, by L. E. Hicks. On some primordial fossils from South-eastern Newfoundland, by J. F. Whiteaves. New pterodactyle from the Jurassic of the Rocky mountains, by O. C. Marsh.

SIEBOLD AND Kölliker's Zeitschrift für WISSENSCHAFTLICHE

ZOOLOGIE.-July 30, 1878. On the Siphonophores of deep water, by Th. Studer. Morphology of the Oxytrichinæ, by V. Sterki. Trichaster elegans, by H. Ludwig. Contributions to a knowledge of the Tomopterida, by F. Vejdoosky. Contributions to a knowledge of the natural history of the Caprellæ, by A. Gamroth.

QUARTERLY JOURNAL OF CONCHOLOGY.-August. List of shells of Iowa, by F. M. Witter.

1 The articles mentioned under this head are usually selected.

THE

AMERICAN NATURALIST.

VOL. XII. NOVEMBER, 1878. — No. 11.

ASPIDIUM SPINULOSUM (SWARTZ) AND ITS VARIE

DUR

TIES.

BY GEO. E. DAVENPORT.

URING several seasons past I have been making some special examinations of the different forms of Aspidium spinulosum as found growing in Middlesex county, Mass., and offer the result not as being decisive in character, but for the purpose of calling attention to the points involved, and inviting further investigations in the same direction.

An opinion prevails with many botanists that the large series. of forms in this protean species so run into each other, and are oftentimes so confusing and difficult to place, that it would be better to ignore all of the so-called varieties and only recognize all forms under the one specific name. How far this opinion may or may not be correct, and founded on scientific principles, possibly this note may help to determine.

I certainly am not in favor of recognizing as a variety any form not possessing some well marked and permanent character to distinguish it from the recognized typical form of any species. I have so often expressed myself on this point that I do not feel under any apprehension of appearing inconsistent in endeavoring to show that the so-called var. intermedium is a good variety at least, if indeed it be not a good species.

The precise distinctions between Aspidium spinulosum Swz., and its var. intermedium have not as yet been clearly enough pointed out, so that the greatest confusion has prevailed in the effort to verify the presence here of true spinulosum, and to discover the differences between it and the variety; the usual assumption having been that nearly if not all of our American plants belonged to the latter form.

VOL XII –NO XI

My own observations tend to convince me that Swartz's plant is by no means uncommon. Be that as it may, plants are found. here abundantly enough that exactly conform to Swartz's description as given by him in his "Synopsis Filicum."

What then is Aspidium spinulosum Swz.? Swartz says of it, "Frondibus bipinnatis, pinnis pinnatifidis pinnatisque, laciniis oblongis acutis serrato-spinulosis, fronde ovato-triangularis; rachis glabra, stipite paleaceo." "Addenda et emendata,” p. 419 to Synopsis Filicum, 1806. This describes in part nearly all of our American forms. Let us analyze the description and see:

1. Fronds twice-pinnate. This is true in many cases of spinulosum, and the varieties dilatatum and intermedium. In large and highly developed specimens of the two last forms the fronds are often thrice-pinnate, and usually appear to be more divided on account of the pinnules being more deeply cut; but the uncertain application of this character to any one particular form renders it unreliable as a specific character, or only of secondary importance.

2. Pinnules pinnatifid, segments oblong, acute spinulose-toothed. Common to all of the forms, and therefore as unreliable as the first character.

3. Frond triangular-ovate. This more clearly belongs to the var. dilatatum than to any other form, although I have had specimens of intermedium that were broadly triangular in outline, and other things corresponding that form might be regarded as Swartz's plant for all there is in the description to the contrary, specimens being found commonly enough that are triangularovate in outline, bipinnate in structure, with smooth rachis and pale-brown scales.

4. Rachis smooth. This is the case with spinulosum and our dilatatum, but in intermedium the rachis is usually finely glandular. It will be necessary, however, to collect specimens early in order to observe this, as the rachis finally becomes smooth. This makes it difficult, if not impossible, to decide to which form Swartz's description was applied without knowing when, and in what state his plants were collected.

5. Stipes clothed with pale brown scales. This is the case, more or less, with all of our forms. The darker scales with blackish centers peculiar to the most highly developed forms are not reliable as a distinctive character.