u 



K. KISHIXOUYE. 



limb presents many wave-like curves. The numljer of these curves 

 corresponds with that of the metameres in which the gland extends. 

 The limb presents a dorsaiJy directed curvature nt each mesoblastic 

 dissepiment. There is thus a dorsal as well as outward curvature 

 over each of these dissepiments. The coxal gland in such a stage of 

 development is found in an embrvo of about the stsige of fig. 17. The 

 further development of the gland I did not follow. 



The coxal gland is probably a degenerated excretory organ, as in 

 development, position, and structure it is similar to the excretory 

 organs of other animals. It is on both sides of the entosternite (tig. 52). 



The coxal o;land of Liinulus is not exactly homoloa'ous with that 

 of the spider. In the latter, tlie gland opens at the base of the third 

 appendage and reaches about to the base of the sixth appenda^i-e, 

 while in Linmlus the gland opens at the base of the fifth nppendage 

 and develops forwards to tlie base of the third ;ippendage. 



Vascular System. 



The chief dcn-sal circidatory vessel is formed from the mesoblastic 

 wall of the cœlomic cavity. As the walls of the lateral halves of 

 the succeeding cœlomic cavities unite gradually, beginniijg with 

 the posterior segments (figs. 15, 10), the dorsal circulatory vessel is 

 formed, pari passu, from the posterior end of the l^ody. Though the 

 walls of the cœlomic cavities on both sides meet in the dorsal median 

 line, they do not fuse together (figs. 17, 43, 44). A longitudinal and 

 many transverse slits separate every cœlomic cavity from its fellow 

 on the opposite side of the same segment, and from the preceding 

 and succeeding cœlomic cavities of the same side (figs. 15-17). The 



