BY J. T. WILSON AND C. J. MARTIN. 665 



criticism of some of our former statements may entitle us again 

 to be heard in reply. 



We have further completed our study of the sweat-glands and 

 ducts and their associated structures, and we propose by means 

 of it to supplement Professor Poulton's account of these interesting 

 objects. 



Upon the whole, as Mr. Poulton points out, our views upon 

 the structure of the push-rods coincide with his own. The only 

 really important subject of dispute concerns the essential nature 

 of the fibiils or filaments which traverse the shaft of the push-rod. 

 Poulton strongly opposes our view that these filaments are nervous 

 in character. He appears to have interpreted our remark that 

 he " failed to recognise the nervous character and connections of 

 the filaments " as reproaching him with imperfect observation. 

 It was certainly not so intended but merely as a statement of a 

 fact, and as such, indeed, Mr. Poulton with some emphasis 

 expresses his entire agreement with it. 



We are very well aware that our opportunities for satisfactory 

 investigation of the tissues of Ornithorhynchus are, in the nature 

 of the case, vastly superior to those usually possessed by investi- 

 gators in Europe. In view of this very fact, however, is not Mr. 

 Poulton's dogmatic assertion that the "nervous character" of the 

 filaments "does not exist" just a little hasty? In regard to the 

 question of their nervous connection we unfortunately did not 

 gather from Mr. Poulton's brief communication that he had 

 "inferred" an actual continuity between nerve-fibres and the 

 filaments in question such as we claimed to demonstrate. In the 

 note itself there does not appear the slightest suggestion of such 

 an inference. The title, "On the tactile terminal organs," &c., to 

 which he appeals as sole evidence of his inference can hardly be 

 taken as giving explicit information upon this particular point. 

 It used to be held for example that auditory nerve fibres ended 

 by continuity with auditory hair-cells. It has been shown pretty 

 conclusively by Retzius, van Gehuchten and others* that these 



" Of. Retzius in V5iolog. Untersuchungen, Neue Folge, iii. & iv.; Verhaudl. 

 (1. Anat. Gesellsch. 1892, p. 63; Anatomischer Aiizeiger, vi. p. 82; Van 

 Gehuchten in La Celhile, viii. 1892. 

 45 



