/ 



72 Vitality and Organization of Protoplasm, 



going transformation through and through, resulting eventually in its 

 self-division. Each germinal center attracts, stage by stage, of its onto- 

 genetic evolution, the requisite complemental material from the general 

 plasmatic fund, until each developing germ has become an entire self- 

 rounded organism, separated from the rest, not by any membrane, but 

 by its own chemical constitution as an individuated whole. In each 

 individuated unit a lively formative process continues its work, often 

 involving the rotation of their entire substance. They then glide round 

 and round one another, the direction of the rotation becoming at times 

 reversed, and at times ceasing altogether, whilst all along the internal 

 motion of granules at different places, and the formation of depurative 

 vesicles, afford proof that the formative commotion is due to chemical 

 activity. Suddenly the adjoining individuals, now fully organized, sep- 

 arate and dart away, each to pursue life on its own account. In this 

 case tlie separating individuals do not finally break through an inclosing 

 membrane, as is the case in some other infusoria. No trace of a mem- 

 brane inclosing the plasmatic sphere is visible during the formative pro- 

 cess, and no trace of such a membrane is left after the individuals have 

 separated. This interesting fact would seem to justify tlie inference 

 that chemical taxis holds the segregated units together until diminish- 

 ing in power with their increasing structural organization its attraction 

 ceases at last altogether, allowing the completely individualized units to 

 sever their connection. I have observed ,on other occasions similar 

 manifestations of chemotaxis in operation between protoplasmic in- 

 dividuals, which I was led to ascribe to complemental chemical affinity 

 between the attracted beings. 



Now, is it not likely that in Metazoa similar ontogenetic commotions 

 and mass-movement, involving the shifting of certain substances and the 

 wandering of certain /^cells^' to different positions; may not these seem- 

 Jng, attractions from a distance be due to essentially the same kind of 

 chemical elaboration and assimilation, as directly witnessed in our Col- 

 poda ? 



FERTILIZATION. 



It has been found that the unfertilized egg-plasm is already bilaterally 

 organized, and also that artificial conditions can incite it to partheno- 

 genetic self-evolution, whereby it undergoes the same normal segmenta- 

 tion as it would have undergone after spermatic fertilization. This 

 being so, what kind of specific influence on ontogenetic evolution has 

 the fertilization of the egg? The intrusion of the spermatozoon can, of 

 course, not be regarded as a mere incitement, which simply sets going 

 the self-evolution of the egg-plasm, as has been actually believed by 

 some biologists. 



The spermatazoon contains evidently as complete an endowment of 

 ontogenetic efficiencies as the egg itself. The bisexual adult organism 

 proves clearly to be a product attained by the intimate blending of male 

 and female germ-plasm. How, then, does tlie germ-plasm of the sperm- 



