1879.] in the anatomy of Peripatus Gapensis. 267 



anatomy a matter of some interest; and through the kindness of 

 Mr Moseley I have had an opportunity of making investigations on 

 some well-preserved examples of Peripatus Capensis, a few of the 

 results of which I propose to lay before the Society. 



I shall confine my observations to three organs. (1) The seg- 

 mental organs, (2) the nervous system, (3) the so-called fat bodies 

 of Mr Moseley. 



In all the segments of the body, with the exception of the first 

 two or three postoral ones, there are present glandular bodies 

 apparently equivalent to the segmental organs of Annelids. 



These organs have not completely escaped the attention of 

 previous observers. The anterior of them were noticed by 

 Grube*, but their relations were not made out. By Saenger-f, as I 

 gather from Leuckart's Bericht for the years 1868-9, these structures 

 were also noticed, and they were interpreted as segmental organs. 

 Their external openings were correctly identified. 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 forgotten. 



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

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

 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 

 shown by their presence are of some interest. Around the seg- 

 mental organs in the feet are peculiar cells richly supplied with 

 trachese, which appear to me to be similar to the fat bodies in 

 insects. There are two glandular bodies in the feet in addition to 

 the segmental organs. 



The more obvious features of the nervous system have been 

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

 consists of large paired supracesophageal ganglia connected with 



'^ "Bau Tou Pcrip. EcTwardii," Archiv f. Anat. u. P/iys., 1853. 

 t Jilotikauer Naturforschcf Sammlunr/, Abth. Zool., 18G9. 



