72 W. WOODLAND. 



sidiary one when the more complicated forms of spicules are 

 concerned. 



Concerning factor (6) this has been so little considered 

 that^ though in all probability it is a very important one from 

 our present standpoint it is impossible to discuss it at any 

 length. It is probable that factor (&) (in conjunction with 

 factor [a]) has a lot to do with producing that adaptation of 

 the form of the spicule to the architecture of the organism 

 (occasionally it is the reverse) which is often so conspicuous. 

 Crystallomorphs plainly exhibit this feature — the presence of 

 an adjacent though separate object to one side, e. g. clearly 

 modifying the shape of the crystallomorph on that side. 

 Moreover, the organism seems to exert a decided influence 

 on the disposition of the spicules in such cases as in certain 

 Kadiolaria, e. g. and therefore similar influences may be at 

 work in more complicated organisms. However, we possess 

 no data as yet in connection with this subject, and beyond 

 making the preceding suggestions it is impossible to say any- 

 thing about it. 



Concerning factor (c) there exist, as already stated, a suffi- 

 cient number of facts which seem to me to indicate that we 

 must rely in the main on this factor (in conjunction with fac- 

 tors (a) and [h) for our future comprehension of spicule forms. 

 It is significant that, of colloidal media, albumen was found 

 by Ord and others to be the most effective in the production 

 of what he terms " coalescence bodies,^^ and what I venture 

 to term crystallomorphs. To gain an adequate idea as to the 

 nature of these bodies it is necessary to refer to the works of 

 Kainey (20, 21), Harting (8), Ord (18, 19), Vogelsang (26), 

 Slack (24), Lehmann (12), Bowman (2), and others on 

 the subject, but for present purposes a few statements 

 descriptive of the nature of some of the simpler crystallo- 

 morphs will suffice.^ Thus Ord, employing albumen and 

 other colloidal media, states that "triple phosphate being 



It is perhaps a fact of some signiGcaiice that tlic most definite and 

 complex forms of calcareous spicules are those containing least organic 

 (horny) substance in their composition. 



