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THE AMEKICAN MONTHLY 



[January, 



zil, Borneo, Ceylon, New Zealand, and 

 the United States. A set of fifty is 

 done up in book form, making a 

 volume of one hundred pages, finely 

 bound and lettered. The student of 

 Algae will find these volumes of 

 much interest, and a great help in 

 the identification of specimens, beside 

 making a valuable addition to a lib- 

 rary and to the herbarium. — F. W. 



o 



Fresh-water Sponges. — In a 

 short note in the Proc. Acad. Nat. 

 Set., of Philadelphia, a number of 

 fresh-water sponges found by Mr. 

 Potts in Fairmount Park, are briefly 

 described. Three distinct species 

 were found ; one, the common green 

 sponge of the neighborhood, resembles 

 in appearance, and in the shape of 

 its dermal spicules and skeleton, the 

 Spongilla lacustris of Europe, but 

 differs from it in having the spher- 

 ules entirely smooth. The second 

 form was first observed as a thin, 

 rust-colored incrustation, but after- 

 wards it was found to consist of 

 spherules forming a continuous layer. 

 This form is the S. fragilis of Leidy. 

 The third form was found upon and 

 around Anacharis and willow roots, 

 matting them together and forming 

 loose masses, several inches in dia- 

 meter, yellowish or green. The 

 spherules were globular, yellow or 

 brown, covered with long birotulate 

 spicules arranged radially, foramen 

 elongated into a flaring tube, and di- 

 vided into two to five tapering, 

 slender tendrils. The sarcode de- 

 composes early in the season. For 

 this species the name S. tentasperma 

 was proposed. 



Archives of Biology. — We take 

 pleasure in calling attention to a 

 new publication, the Archives de 

 Biologic^ edited by Edouard Van 

 Beneden and Charles Van Bam- 

 beke. The eminence of these gentle- 

 men will commend the work to the 

 scientific world, and we predict for it 

 a hearty welcome from all students of 

 biology. It is a quarterly publication. 



which, at the end of the year, will form 

 an octavo volume of about 600 pages, 

 and 20 or 25 plates. The subscrip- 

 tion price is 30 francs ($6.00) or 9 

 francs for each number. 



The first number contains some 

 valuable contributions, among which 

 may be mentioned the following : 

 " Physiology of Muscles and Nerves 

 of the Lobster," an article which 

 gives the results of a long series of 

 experiments upon the mechanics of 

 contraction, and the associated ther- 

 mal, chemical and electrical phe- 

 nomena, and new investigations con- 

 cerning the propagation of nervous 

 impulses. The conclusions reached 

 are that there is a complete identity 

 in properties between the muscles 

 of the lobster and those of the frog ; 

 and as regards the motor nerves, the 

 difference is found in the rapidity of 

 transmission, this being much slower 

 in the lobster. There is an excellent 

 article on the "Development of the 

 Placenta of the Rabbit," and another 

 of great interest, entitled: " New Com- 

 munications upon the Living Carti- 

 laginous Cells," by M. W. Schleicher. 

 The article on "Ossification of the In- 

 ferior Maxillary and on the Constitu- 

 tion of the Dental System" we reserve 

 for a longer notice in our next num- 

 ber. M. E. Van Beneden contributes 

 an article of 83 pages, entitled " Re- 

 searches on the Embryology of Mam- 

 mifers," which is accompanied by 

 three large, folded plates, beautifully 

 colored. The last article is a descrip- 

 tion of the Bacillus of Leprosy {^Ba- 

 cillus leprcR) which is figured. 

 o 



The Northern Microscopist. — 

 We are pleased to notice another 

 English periodical devoted to Micro- 

 scopy, which begins its career with 

 January, 1881. It is named The 

 Northern Microscopist, and the Editor 

 is George E. Davis, F.R.M.S., F.LC, 

 F.C.S., etc., etc. We have long 

 thought that there was ample room 

 for another microscopical journal in 

 England, which should occupy a place 

 which the Journal of the Roycil Mi- 



