ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 461 



Internal Peristome of Mosses.* — M. Philibert continues his studies 

 on the structure of the peristome. He states that the internal peristome 

 is always constructed on one general plan, except in the Funariacese ; 

 nevertheless in the various genera, and even between the species, certain 

 differences in its structure exist. The dorsal network is always the 

 same, although more or less apparent ; but the meshes of the ventral 

 network vary in number and form. This form is usually more or less 

 trapezoidal, but they are often pentagonal or hexagonal. The number 

 of rows corresponding to each of the teeth is also very variable ; in 

 the genus Milium there are four or five, while in most of the Hypnacets 

 there are only three or four. Other differences result from the entire 

 absence or from the feeble dimensions of certain elements in the normal 

 structure. The author then describes in detail the structure of the 

 internal peristome as found in the Meesese, In this group of mosses the 

 peristome has exactly the same origin as in Mnium and Bryum, and its 

 elements are disposed on the same plan ; but a difference in appearance 

 is caused by the inequality of the thickening of the primitive elements. 



Antherozooids of Hepaticse.f — M. Leclerc du Sablon has investigated 

 the development of the antherozooids of Hepaticee in 31etzgeria furcata, 

 Badula comjplanata, Frullania dilatata, and Alicularia scalaris. They 

 are formed at once from the nucleus and from the protoplasm of the 

 mother-cell. The body of the antherozooid does not correspond solely 

 to the nucleus of the mother-cell, but to nucleus phis protoplasm. There 

 is a change in properties and structure. The body of the antherozooid 

 is more refractive and more homogeneous than the protoplasm of the 

 nucleus, and is less susceptible to staining, especially at the climax of 

 its formation. The mother-cell undergoes a total renovation in forming 

 the antherozooid. 



Characeae. 



American Characeae. J— The first part of Dr. T. F. Allen's mono- 

 graph of American Cbaracere is occupied by an Introduction, Morphology, 

 and Classification. A complete account is given of the structure and 

 development of the various organs, vegetative and reproductive, illustrated 

 by very numerous and well-executed woodcuts. For the female organ 

 before fertilization the term " sporophydium " is proposed, its cellular 

 envelope being termed the " sporostegium." A clavis follows of all the 

 American species belonging to the genera Nitella (79), Tolypella (13), 

 Lychnotliamnus (3), and Cliara (62). Lamprothamnus does not occur 

 in America. 



"With regard to the species described as Tolypella Macounii,§ Dr. 

 Allen now |j regards it as a Nitella. 



Algae. 

 Attachment-organ of Algse.lf — Dr. H. F. G. Stroemfelt calls atten- 

 tion to the different modes of structure and development of the basal 

 portion of the thallus of algse, by which they attach themselves to a sub- 



* Rev. Bryol., xv. (1888) pp. 6-12. Cf. this Journal, ante, p. 263. 



t Comptes Rendus, cvi. (1888) pp. 876-8. 



X Allen, Dr. T. F., ' The Ckaracese of America,' Pt. 1, 64 pp. and 55 figs., New 

 York, 1888. 



§ See this Journal, ante, p. 90. || Bot. Gazette, xv. (1888) p. 11. 



If Naturv. Studcntsallsk. Upsala, May 13, 1887. See Bot. Gentralbl., xxxiii. 

 (188S) pp. 381 and 395. 



