144 THE TESTES, BY V. LA VALETTE ST. GEORGE. 



instances be observed cells with nuclear structures, and with 

 long and stiff rays Daphnia rectirostris. The genus Poly- 

 phemus possesses uncommonly large stellate cells. 



In the seminal corpuscles of these animals, as well as of 

 other Daphnise, Leydig observed transient amoeboid move- 

 ments. 



DECAPODA. We have been made acquainted with the very 

 peculiar seminal corpuscles of the Decapoda by the observa- 

 tions of Henle, v. Siebold, Kblliker, Frey, and Leuckart. They 

 are small cell-like, thick bodies, that give off fibrous processes 

 like rays. Owsjannikow made the important observation that 

 these rays can be withdrawn, so that the corpuscle can assume 

 a spheroidal form. 



Mysis possesses capilliform spermatic elements (v. Siebold, 

 Frey, and Leuckart). 



The spermatozoa of Crangon and Palcemon, according to 

 v. Siebold's investigations, form flattened vesicles, from the 

 centre of which a short spur projects. 



AMPHIPODA AND ISOPODA. Those of Amphipoda and Iso- 

 poda are stiff threads that are either pointed at both ex- 

 tremities (Oniscus), or have at one end a cylindrical pointed 

 appendage (Asellus). In these woodlice the upper part of the 

 thread is angularly bent, and easily breaks near the head ; a 

 circumstance which has caused Zenker to ascribe two forms of 

 spermatozoa to these animals. 



ARACHNIDA. In the different groups of this class great 

 diversity exists in regard to the form of the seminal elements. 

 According to Kolliker, Scorpio Europceus possesses spermatozoa 

 of simple hair-like form that move with activity ; those of the 

 Tardigrada are fusiform with an oval head, from whence pro- 

 ceeds two vibrating terminal threads (Doyere, Greeff). 



Amongst the Araneidce we find motionless round or reni- 

 form bodies, with round or elongated nuclei : Tegenaria, 

 Lycosa (v. Siebold). 



The Acaridce have spheroidal, fusiform, club-shaped, and 

 rod-like spermatozoa Trombidium, Bdella, Hydrachna, Ix- 

 odes (v. Siebold). In the contents of the testis of Alax, 



