394 M. E. Grube on the Capitellse 



channel of Copenhagen enabled me, in the few days of my resi- 

 dence there, to repeat these extremely interesting observations 

 on a series of specimens ; but although we then (at the end of 

 July) still found ova in many females, we did not succeed in 

 detecting spermatozoa in the testes of the males : these Oersted 

 had represented of a more fusiform shape than Van Beneden, 

 and with a more acute anterior extremity and a shorter terminal 

 filament. That I did not at once comply with Oersted's request 

 to make known these observations was due partly to the want 

 of a micrometer ; for it appeared to me to be necessary to give 

 the diameter of the corpuscles which floated in the somatic ca- 

 vity. A second independent confirmation of Van Beneden's in- 

 vestigations has lately been given by Claparede*, who, without 

 any acquaintance with them, observed the same species in the 

 Hebrides, but was not able any more than myself to subject the 

 sexual peculiarities to a complete examination. 



As regards the fluid of the somatic cavity and the red corpus- 

 cles contained in it in such abundance, Claparede also expresses 

 himself in favour of its analogy with the blood. Van Beneden 

 describes the corpuscles as " globules/' and says that their form is 

 lenticular; I convinced myself, during their flow from a wound 

 in the wall of the body, that they are disciform and circular, as 

 they show to the observer sometimes their broad surface and 

 sometimes their margin. Claparede also calls them " disques," 

 and I could almost think that they are biconcave like the blood- 

 corpuscles of the Mammalia : that they contain a true nucleus, 

 as stated by Van Beneden and Claparede, could not be ascer- 

 tained positively by Prof. Reichert and myself — what might have 

 been taken for a nucleus appearing only to adhere accidentally, 

 and to be one of the corpuscles which also occur free in the so- 

 matic cavity ; and the employment of acetic acid did not succeed 

 in producing a more distinct appearance of a nucleus. By the 

 action of this reagent the disks scarcely became somewhat 

 smaller ; and whilst their outer margin still remained circular, 

 their interior appeared as if crumpled or granulated, minute 

 sharply-defined granules being distinguishable therein. 



In ether they become decidedly more irregular, and the mar- 

 gin and interior become more sharply discriminated. I must, 

 however, remark that I have observed all this only upon Capi- 

 tella. which were sent to me in Breslau by the kindness of Prof. 

 Van Beneden, and which, being favoured by the December 

 weather, arrived indeed still living, but by no means lively in 

 appearance; nevertheless even the broken or half-dead specimens 

 exhibited no essential difference in this respect. The diameter 



* Memoires de la Soc. de Phys. et d'Hist. Nat. de Geneve, 1861, p. 110, 

 pl.l. 



