FORMS OF LIFE 



the origin of these few geometrically definable types, 

 and the cause of their divergence. 



In this important and difficult question we find a great 

 variety of opinions and a strong leaning to dualistic and 

 mystic theories. Educated laymen, who have only a 

 partial and imperfect acquaintance with the biological 

 facts, think that they are justified here in appealing to a 

 supernatural creation of forms. They contend that only 

 a wise creator, following a rational and conscious design, 

 could produce such structures. Even distinguished and 

 informed scientists lean in this matter towards mystic 

 and transcendental ideas ; they believe that the ordinary 

 natural forces do not suffice to explain these phenomena, 

 and that at least for the first construction of these 

 fundamental types we must postulate a deliberate 

 creative thought, a design, or some such teleological 

 cause, and therefore consciously acting final causes. 

 So say Nageli and Alexander Braun. 



In direct opposition to this, I have ever maintained 

 the view that the action of familiar physical forces — 

 mechanical efficient causes — fully suffices to explain the 

 origin and transformation of these fundamental types, 

 as well as for all other biological and inorganic processes. 

 In order to understand this monistic position thoroughly, 

 and to meet the errors of dualism, we must bear in mind 

 always the radical processes of growth which control all 

 organic and inorganic configuration, and also the long 

 chain of advancing stages of development, which lead us 

 from the simplest protists, the monera, to the most 

 advanced organisms. 



The unicellular organisms exhibit the greatest variety 

 from the promorphological point of view. In the single 

 class of the radiolaria we find all imaginable geometrical 

 types represented. This is seen in a glance at the one 

 hundred and forty plates on which I have depicted 

 thousands of these graceful little protozoa in my mono- 



