54 



Further, the »cellular charactercc (which he doubts p. 454) of the 

 coarsely granular, columnar cells — called by him »calceo-cuticular« 

 glands — is readily demonstrated by a simple method, and one which 

 is essential to the study of cell-shape , viz. maceration in bichromate 

 of potash or some such reagent. 



But since he is unable to recognise the unicellular gland cells 

 (»goblet-a or »mucus- cells«) in the ordinary hypodermis , what wonder 

 that he is confused by the more complicated structure of the clitellum? 



Again, wherein lies the difficulty (p. 456) of seeing the capil- 

 laries traversing the layer of clitellar cells? For having recognised 

 these he is good enough to congratulate Clap are de! 



With regard to the process of copulation in the Earthworm — a 

 matter to which I have paid some attention — I would ask Mr. Cole 

 one question: — Has he ever observed two worms engaged in the 

 process? If he had, he would not need to have troubled to discuss the 

 various statements of less observant authors — statements which , cer- 

 tainly, are not entirely accurate : but , after a prolonged argument to 

 show the futility of their statements, Mr. Cole puts in their place a 

 theory of his own as to the passage of the spermatozoa from one worm 

 to another : a theory founded on no firm basis of fact, but on »proba- 

 bilities«. 



In two individuals out of some hundreds he discovers a duct — 

 inflation of cuticle — passing from the 15th segment to the tubercula 

 pubertatis : he believes the male duct does not open to the exterior 

 in segment 15th but that this new duct does all he wants from it — as 

 it explains to him the use of the tubercula. He is not aware, that 

 these tubercula are (as a matter of observation) used during copulation 

 for the purpose of fixing the two worms together. 



His remarks on cocoon formation »add nothing to the little already 

 known« (to quote his own words) . He does not appear to be aware of 

 what is known, or he would scarcely have suggested — imagined, 

 evolved from his inner consciousness — that the cocoon is formed in 

 two separate curved »sheets«, the edges of which are then cemented 

 together. Another question — Has he seen the cocoon oi L. Jier- 

 cw^ews, or other Earthworm? 



In the process of »copulation« two matters, which must be kept 

 distinct, have to be decided: 1) how the worms become joined together, 

 2) what happens to the spermatozoa. Further, this »Copulation« must 

 be differentiated from another double process viz. the formation of 

 the cocoon and the laying of eggs. 



It must be confessed that we are still in some doubt as to the 

 exact series of occurrences during these processes; but we may be 



