38 



BIOLOGY OF THE PROTOZOA 



Phalansterium digitatum (Fig. 20). 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 division of the cells, the aggregate forming an organ-pipe-like 

 arboroid colony. Gregaloid colonies, finally are fortuitous aggre- 

 gates of previously independent individuals found mainly amongst 

 the rhizopods and Heliozoa, or in parasitic flagellates under adverse 

 environmental conditions (Spirocha^tes, Trypanosomes) . The origin 

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

 of reproduction. 



(5) Inheritance.— 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 transmitted by 



B ccte8!ragrg-;:^^^a5ie> 



Fig. 17. 



-Types of shells of Foraminifera. A, B, side and ventral aspects of Cornu- 

 spira sp.; C, and D, types of Nodosaria. (After Carpenter.) 



inheritance. Fantastic types such as Discomorpha pectinata, 

 Entodinivvi caudatum, or Phryocystis caudatiis are not uncommon. 

 In its last anal\'sis form depends upon the chemical and physical 

 make-up of the protoplasm and its polarity which signifies a specific 

 protoplasmic organization and interaction of different protoplasmic 

 substances. A minute fragment of Uroleptus mohilis is difficult 

 to distinguish from a similar fragment of Dileptus gigas, yet the 

 former develops into a perfect Uroleptus the latter into Dileptus. 

 The encysted forms of many types are impossible to identify until 

 the cysts are opened and vital processes begin again. These facts 

 indicate that the finer or ultimate composition of protoplasm is 

 dift'erent in difterent forms and specific for each species, and justify 

 the view that there are as many kinds of protoplasm as there are 

 species of Protozoa, Metazoa or living things generally. Considera- 

 tions of this nature inevitablv lead us into the lines of thought 



