20 



MORPHOLOGICAL DEVELOPMENT 



Where, as in types like these, the morphological units 

 show an inherent tendency to arrange themselves in a man- 

 ner that is so far constant as to give characteristic propor- 

 tions, we may say that there is a recognizable compound in- 

 dividuality. Considering the Thallogens that grow in this 

 way, apart from their kinships, and wholly with reference to 

 their morphological composition, we might not inaptly de- 

 scribe them as pseudo-foliar. 



184. Another mode in which aggregation is so carried 

 on as to produce a compound individuality of considerable 

 definiteness, is variously displayed among other families of 

 Algce. When the cells, instead of multiplying longitudin- 

 ally alone, and instead of all multiplying laterally as well as 

 longitudinally, multiply laterally only at particular places ; 

 they produce a branched structure. 



Indications of this mode of aggregation occur among the 

 Conferees and simple plants akin to them, as shown in Figs. 

 22, 23. Though, in some of the more developed Alyce which 

 exhibit the ramified arrangement in a higher degree, the 

 component cells are, like those of the lower Algae, united to- 

 gether end to end, in such way as but little to obscure their 

 separate forms, as in Cladophora Hutchinsioe, Fig. 31 ; they 



nevertheless evince greater subordination to the whole of 

 which they are parts, by arranging themselves more method- 



