ZOOLOGY AND BOTANY, MICROSCOPY. ETC. 953 



just as they are in the young of A. aquaticus : those of the other species 

 are not known. 



Other juvenile characters which may be noted, are the reduction in the 

 numbers of joints of the outer antennae, and the presence, last of all, of 

 pigment on the head, and especially near the eye. 



Australian Cladocera.* — It is a well-lmown fact that the eggs of various 

 fresh-water animals (notably those of Entomostraca) will withstand long 

 desiccation, but still the experiments detailed by Prof. G. O. Sars have con- 

 siderable interest. A correspondent sent him some dried mud from the 

 shores of a fresh-water lake in tropical Australia. This mud was placed 

 in water, and from it were hatched out one Copepod. one Ostracode, a 

 species of Polyzoan, apparently belonging to the genus Plumafella, and five 

 species of Cladocera. These last are made the subject of an exhaustive 

 paper. The species all belonged to genera [Daphnia, Diaphanosomn, Cerio- 

 daphnia. Moina, and Lei/digia) already known from European waters, and 

 the species of these genera themselves closely resemble those of the anti- 

 podes, notwithstanding that they came from localities thousands of miles 

 apart, and which have entirely different environments. These facts recall 

 to the author the close similarity, even identity, of the crustacean species 

 of Italy and Norway, and he concludes that one cannot lay too great stress 

 on the importance of birds in the distribution of these forms. 



Vermes. 

 a. Annelida. 



Anatomy of Earthworms. f — Mr. F. E. Beddard describes in Eudrilus 

 syhicola n. sp. an arrangement of the ovary and oviduct in which these 

 parts occupy precisely the reverse positions to those figured by Prof. Perrier ; 

 in fact, the oviduct lies in front of and not behind the ovary. Attention 

 is further drawn to the fact that the ovary and its duct are connected with 

 one another, and that, therefore, there is not the difference between Annelids 

 and Hirudinea which is ordinarily stated to obtain. The organs called 

 testes by Prof. Perrier are really the vesiculae seminales.^ The terminal 

 portion of the male genei*ative apparatus of Eudrilus offers some points of 

 interest ; the glandular nature of the prostate gland is masked by the great 

 development of its muscular layers, which give to it its characteristic 

 nacreous appearance ; the thick muscular coat is formed, for the greatest 

 part, by longitudinal fibres ; the glandular tissue is divided into two layers, 

 which jiresent an unmistakable resemblance to the epidermis of the clitellum ; 

 in its posterior half the prostate is divided into two independent tubes; 

 one contains the continuation of the lumen of the prostate, and the other at 

 first contains merely a mass of glandular cells ; a lumen is soon developed. 

 The vasa deferentia, afcer entering the prostate, become very fine tubes. 

 Each portion of the prostate becomes continuous with a narrow tube that 

 leads to the penis ; this last is a muscular process of the walls of the bursa 

 copulatiix, and contains a median canal which is continuous with the lumen 

 of the duct of the prostate gland. In the possession of a muscular coat 

 to the vas deferens Eudrilus presents another point of resemblance to the 



* Forh. Vidensk. Selsk. Christiania, 1886, 49 pp. and 8 pis. Cf. Amer. Natural., xxi. 

 (1SS7) p. 186. 



t Proc. Zool. Soc. Lond., 1887, pp. 372-91 (1 pi.). 



X It seems to be but little known that in hia ' Forms of Animal Life,' the late 

 Professor Rolleston correctly figured the position of the testes in the common earth- 

 worm, 80 that he comes between Hering (1857, not 1852) and the rediscovery by 

 Professor Bourne. 



