ANATOMY AND PHYSIOLOGY. Moll. 15 
fresh-water Bivalves by F. Hazay, Mai. Bl. (2) iv. pp. 132-160. Unio 
jnctorum, tumidus, and hatavus reach, in the second year of their life, a 
length of 7-25 millimetres, in the third 8-34, in the fourth 29-73, in the 
fifth 36-83. Anodonia grows more quickly in the first year. 
Note on the breeding habits of the European and American Oyster ; 
Am. Nat. xv. pp. 57 & 58. 
Self-fecundation of fresh-water Bivalves probable according to F. Hazay, 
Mai. Bl. (2) iv. p. 164 and following. 
Mutual fecundation in Planorhis spirorhis, carinatiis^ and corneuSy 
observed ; id. 1. c. p. 50. 
Eggs of Limncea and Ph^sa, with 2-10 yelks; id. 1. c. pp. 52-56. 
Generative organs and spawn of Onchidium described; J. Joyeux- 
Laffuie, C. R. xcii. p. 146. 
Hybrids of some species of Partula'y Hartman, Bull. Mus. C. Z. ix. 
p. 173. 
The first stages of development in Neritina fluviatilis, from the seg- 
mentation of the yelk to the shutting of the blastopore, are described by 
F. Blociimann, Z. wiss. Zool. xxxvi. pp. 125-174, pis. vi.-viii. Abstract 
in J. R. Micr. Soc. (2) i. pp. 877 & 878. 
The development of Limax cainpestris (Binn.), with special regard to 
the first changes in the egg, pro-nucleus and cleavage, &c., described by 
E. L. Mark, Bull. Mus. 0. Z. vi. pp. 173-625, 5 pis. Abstract in J. R. 
Micr. Soc. (2) ii. pp. 178 & 179. 
The first stages of development in the egg of Limncea stagnalis^ from 
the disappearance of the germinal vesicle to the first appearance of the 
chief organic systems, is described and discussed, with criticisms on the 
statements of Lereboullet, Ganin, E. R. Lankester, and others, by W. 
WoLFSON, Bull. P^tersb. xxvi. pp. 79-97, or Mel. Biol. x. pp. 351-377, 
with numerous woodcuts. It is the abstract of a larger paper, published 
in 1879 in Russian. 
Young individuals of Limncea coming from the same string of eggs 
exhibit great differences in time and degree of growth ; the relation of 
growth to the volume of water in which they are bred, as surmised by 
Semper, is not confirmed. Hazay, Mai. Bl. (2) iv. pp. 220 & 221. 
10 . Growth of Shell. 
H. Grabau discusses the spiral line, and states with regard to the 
objections made by J. F. Blake (Phil. Mag. and J. of Sci. vi. 1878) that 
the curve termed by Naumann ‘ Conchospiral,’ after simplifying some 
equations, is a most apt expression ; he exemplifies it by measurements 
in an Ammonite, Arcestes intus-labiatus ; the deviations of the measure- 
ments from the calculation are only trifling, and compensate each other. 
SB. Ges. Leipzig, viii. pp. 23-32. [c/. Zool. Rec. ix. 1872, p. 112]. 
11 . Biology. 
Notes on the sea Mollusca kept alive in the Aquarium at Frankfort by 
F. Richters, ‘ Das Aquarium des zoologischen Gartens zu Frankfurt- 
a.-M.,’ Schulprogramm, 1881. 
