PARASITIC COPEPODS—CALIGID.E— WILSON. 



525 



OO.— UVAKV 



ENLAKGED. 



(IF CALIGUS BONITO 

 0. d., OVIDUCT. 



rior end coiinoctcd with the ovidiu-t just in front of the external open- 

 ing. This oroun is a cement g-land (c. g., fig-. 29) and secretes the 

 material forming the external egg 

 tubes. 



This is undoubted!}" *'the flat, cylin- 

 drical organ, usually as broad as the 

 external oviduct, and living along the 

 central portion of the al)domen," re- 

 ferred to ))y Pickering and Dana, and 

 whose function they could not in- 

 terpret. 



Its sha]3e differs considerably in the 

 different genera and species, and will 

 be descril)ed for each, so far as known. 

 The general features, however, are 

 the same for all species. It consists 

 of a long and flattened tube, which is 

 decidedly clul^-shaped in most species 

 rather than cylindrical. It is usually 

 inclined inward toward the mid line 



and reaches forward nearly to the anterior margin of the genital segment. 

 The lumen of the tube is narrow and surrounded by a ver^^ thick 



and transparent wall. It is fv^rther 

 divided into flattened cells by trans- 

 verse partitions, the cells being 

 strongly rounded at the edges and 

 thus looking very similar to the eggs. 

 So great is this resemblance that the 

 glands, though perfectly visible in 

 many species, are easily mistaken for 

 a part of the convolutions of the ovi- 

 duct. But they can be easily dis- 

 tinguished by the fact that in most 

 species the central lumen is consider- 

 ably narrower than the oviduct, while 

 in all species the anterior end is 

 closed. 



In sections the ovary is seen to be 

 made up of a long, narrow tul)ule 

 coiled up into a dense snarl or >skein. 

 The tubule is made up of a structure- 

 less membrane lined with germinal 

 epithelium. The latter gives rise to 

 the eggs, which are formed in the 

 lumen of tlu^ tubule, and which, when sufficiently developed, bivak 

 through the walls and pass into the oviduct. 

 Proc. N. M. vol. xxviii— 04 o4 



Fig. 31.— (iK.NITAI, SlOci.ME.NT OK Lepeoph- 

 THEIRVS EDW AKD.SI JUST AFTER THE 

 HATCHING (IF THE EGGS AND THE 

 THROWIN(; (IFF OF THE EGG-CASES. O. U., 

 OS UTERI; U., UTERUS. 



