486 DEVELOPMENT OF ELASMOBRANCH FISHES. 



examples, and sometimes fairly well in old ones, of either sex 1 . 

 There is generally in each segment a second Malpighian body, 

 which forms the commencement of a tubulus joining that from 

 the primary Malpighian body, and, where the segments are 

 larger, there are three, and possibly in the hinder segments of 

 the Wolffian gland and segments of the kidney proper, more 

 than three Malpighian bodies. 



The accessory Malpighian bodies, or at any rate one of them, 

 appear to have curious relations to the segmental tubes. The 

 necks of some of the anterior segmental tubes (PI. 20, fig. 5) 

 close to their openings into the primary Malpighian bodies are 

 provided with a small knob of cells which points towards the 

 preceding segment and is usually connected with it by a fibrous 

 band. This knob is most conspicuous in the male, and in very 

 young animals or almost ripe embryos. In several instances in 

 a ripe male embryo it appeared to me to have a lumen, and to 

 be continued directly forwards into the accessory Malpighian 

 body of the preceding segment. One such case is figured in 

 the middle segment on PL 20, fig. 5. In this embryo segmental 

 tubes were present in the segments immediately succeeding 

 those connected with the vasa efferentia, and at the same time 

 these segments contained ordinary and accessory Malpighian 

 bodies. The segmental tubes of these segments were not, how- 

 ever, connected with the Malpighian body of their proper seg- 

 ment, but instead, turned forwards and entered the segment 

 in front of that to which they properly belonged. I failed to 

 trace them quite definitely to the accessory Malpighian body 

 of the preceding segment, but. in one instance at least, there 

 appeared to me to be present a fibrous connection, which is 

 shewn in the figure already referred to, PI. 20, fig. 5, r. st. In 

 any case it can hardly be doubted that this peculiarity of the 

 foremost segmental tubes is related to what would seem to be 

 the normal arrangement in the next few succeeding segments, 

 where each segmental tube is connected with a Malpighian body 

 in its own segment, and more or less distinctly with an accessory 

 Malpighian body in the' preceding segment. 



1 My observations on this subject completely disprove, if it is necessary to do so 

 after Professor Semper's investigations, the statement of Dr Meyer, that segmental 

 tubes in Scyllium open into lymph organs. 



