658 POINTS IN THE ANATOMY OF PERIPATUS CAPENSIS. 



mental organs. Their external openings were correctly identi- 

 fied. They are not mentioned by Moseley, and no notice of 

 them is to be found in the text-books. The observations of 

 Grube and Saenger seem, in fact, to have been completely for- 

 gotten. 



The organs are placed at the bases of the feet in two lateral 

 divisions of the body-cavity shut off from the main central 

 median division of the body-cavity by longitudinal septa of 

 transverse muscles. 



Each fully developed organ consists of three parts : 



(1) A dilated vesicle opening externally at the base of a 

 foot. 



(2) A coiled glandular tube connected with this and subdi- 

 vided again into several minor divisions. 



(3) A short terminal portion opening at one extremity into 

 the coiled tube (2) and at the other, as I believe, into the body- 

 cavity. This section becomes very conspicuous in stained 

 preparations by the intensity with which the nuclei of its walls 

 absorb the colouring matter. 



The segmental organs of Peripatus, though formed on a type 

 of their own, more nearly resemble those of the Leech than of 

 any other form with which I am acquainted. The annelidan 

 affinities shewn by their presence are of some interest. Around 

 the segmental organs in the feet are peculiar cells richly supplied 

 with tracheae, which appear to me to be similar to the fat bodies 

 in insects. There are two glandular bodies in the feet in addi- 

 tion to the segmental organs. 



The more obvious features of the nervous system have been 

 fully made out by previous observers, who have shewn that it 

 consists of large paired supraoesophageal ganglia connected with 

 two widely separated ventral cords stated by them not to be 

 ganglionated. Grube describes the two cords as falling into one 

 another behind the anus a feature the presence of which is 

 erroneously denied by Saenger. The lateral cords are united by 

 numerous (5 or 6 for each segment) transverse cords. 



The nervous system would appear at first sight to be very 

 lowly organised, but the new points I believe myself to have 

 made out, as well as certain previously known features in it 

 appear to me to shew that this is not the case. 



