314 SECONDARY CELLS. 



yellow colour, and especially in the branchlets being 

 set in close whorls, like the Horsetail among plants. 

 These branchlets are slender, and look to the naked 

 eye like bristles, closely girding the stem through- 

 out its length. The polype-cells are confined to 

 them, and are arranged along the upper or inner 

 side, as they form an acute angle with the stem. 

 The cells are small funnel-like cups, and among 

 them are interspersed, on the same aspect of the 

 branch, more numerous minute cellules, deep in 

 proportion to their width, which exactly resemble 

 those on PI. setacea. The use of these secondary 

 cells has not been explained. Their constancy and 

 number, I think, preclude the supposition that they 

 are abortive cells, as Dr. Johnston suggests. Each is 

 inhabited by what seems a living tenant, destitute of 

 tentacles, connected organically with the common core. 

 As more perfect observation is continually finding a 

 bisexual distinction among animals in which it was 

 before unsuspected, may it not possibly exist in these 

 zoophytes, and may not these minute cells be those of 

 the males ? In the Hotifera, the male is always 

 smaller, and always destitute of the digestive system ; 

 this might perhaps explain the absence of tentacles in 

 the small pol)^e. (See Plate XXI. fig. 1.) 



I could not find one specimen that contained living 

 polypes ; but several were crowded with the egg-bear- 

 ing vesicles. These are rather large, glassy, some- 

 what oval, but more flattened on the inner side, and 

 cut off with an oblique aperture, on the same aspect. 

 (Fig. 2.) They are seated, with a small stalk, in the 

 axils of the branchlets ; and have a false bottom, evi- 



