INTRODUCTION 



39 



fruticulosa, Anthophysa vegetans (Fig. 21) or Phalansterium digi- 

 iatum (Fig. 22). In Rhipidodendron splendidum the gelatinous 

 branches, colored brown or red by oxide of iron, are arranged in 

 parallel rows, spreading out fan-like as they increase with divi- 

 sion of the cells, the aggregate forming an organ-pipe-like arboroid 

 colony. Gregaloid colonies, finally, are fortuitous aggregates of 

 previously independent individuals found mainly amongst the rhizo- 

 pods and Heliozoa, or in parasitic flagellates under adverse envir- 

 onmental conditions (Spirochetes, Try panosomes) . The origin of 

 gregaloid colonies is not connected in any way with the manner of 

 reproduction. 



Fig. 20. 



-Type of flagellate colony. Codosiga cymosa Kent, an arboroid colony 

 of collared flagellates. 



The combination of all of the above factors effective throughout 

 past ages has resulted in fixed, complex forms which, as in Metazoa, 

 are today associated with the germinal make-up of the protoplasm 

 or genotype, and are transmitted by inheritance. 



B. Protoplasmic Structure.— All protoplasm contains the same 

 fundamental chemical elements — C, H, N, O and P— which are 

 necessary for the performance of vital activities. With these are 

 associated mineral elements of one kind or another— Na, K, Ca, 

 Mg, Fe, S, etc., usually as salts of different kinds, and water. 



In its last analysis form depends upon the chemical and physical 

 combinations of these elements which indicate specific protoplasmic 



