7 6 



HENRY FARNHAM PERKINS. 



surface of the larvae was seen to be covered with a number of 

 thorn-like points, which were evidently the ectodermal cnidocils of 

 the polyp*(Fig. i). There was no sign -of the nematocysts, these 



. ' . ' 



FIG. 2. 



having disappeared early in the degeneration of the tissues. The 

 permanence of the cnidocils is an interesting point in the degen- 



erative changes through which these larva; were seen to pass. 

 It gives a suggestion of the degree to which the tissue is stiffened 

 and specialized to form these trigger-organs. From time to time 



