INVERTEBKATA, CRYPTOGAMIA, MICROSCOPY, ETC. 949 



The great comparative length of the body of this species distin- 

 guishes it from known forms of Apis, while its carapace is relatively 

 smaller and armature less developed. 



Vermes. 



Genital Glands and Segmental Organs of the Polychseta.* — In 

 continuing, in a further number of M. Lacazc-Duthiers' ' Archives,' 

 his further account of this subject, M. Cosmovici deals with it in a 

 comparative manner. 



The result of his researches may be thus summed up : — Taking 

 for exami)Ics Arenicola ptscatorum and Terehella giganfea, we find that 

 the " pouches of the body-cavity " are comijosed of two jmrts ; one is 

 voluminous and glandular, comparable to the molluscan organ of 

 Bojanus ; plexuses of blood-vessels are found in its wall, its interior 

 is lined by a very thick layer of pigmented cells, the most superficial 

 of which have vibratile cilia ; the organ communicates with the 

 interior by a pore, and crystals of uric acid are to be found in it. 

 The second portion is a bell-shai:)cd organ, with two lips ; one of 

 these, more or less richly ciliated, is traversed by a blood-vessel ; the 

 organ is continuous with a funnel of varying length ; connected with 

 the glandular portion, it is obviously a segmental organ, and serves as 

 the oviduct in the female and the sperm-duct in the male. In the 

 Serpulidse and Hermellidte the two jiarts are distinct. In the 

 sedentary Annelids we find, then, two kinds of organs. The organs 

 of Bojanus vary in their number and disposition in the different 

 genera and species. The segmental organs, which may or may not be 

 connected with the organs of Bojanus, similarly diftcr in different 

 forms ; their function is to collect the generative products which float 

 in the coelom and to pass them outwards. The more the animal 

 rises in the scale of development of the Annelidan type the closer is 

 the connection between the two sets of organs ; the sedentary are 

 more elaborately developed than the errant forms, and thus it is in 

 them that the two parts are more closely connected. With the 

 exception of the two families already mentioned — the Serpulida; and 

 the Hermellidie — the segments of the body greatly lose their " indi- 

 viduality." 



As to the genital glands, the researches of the author have 

 convinced him that there are two organs of this kind, both male and 

 female, and that tliey are constant in position. Only in the " beau 

 temps " do they become visible ; they are racemose and attached to a 

 blood-vessel ; each acinus of the glnnd is surrounded by a delicate 

 membrane, capable of distension. The nuclei seen in the contained 

 pr()to2)laHra are the germinal spots of tho future ova ; around these 

 nuclei the amorphous pr()toi)lasm becomes collected, and the ova are 

 driven forward by the develoinnent of fresh protophism at the base of 

 each acinus. The ripe eggs fall into the cavity of the body and 

 CKcai)C to the exterior through the ducts of the segmental organs. 

 Tlie testes present a similar history. The genital glands are to be 



* Sec this .IiMunal, ui/c, p. 63."). 



