Vitality and Organization of Protoplasm. 75 



units, called '^determinants'' by Weismann, wliose biophores arc sup- 

 posed at the right moment and at the exact stage of development to 

 scatter among the somatic biopliors as formative germs, and to deter- 

 mine the specific differentiation of the cellular substance; these deter- 

 mining biophores could accomplish this wonderful feat only by assimil- 

 ating the inditferent biophores of the somatic or morpho-plasm, using 

 them for their own self-multiplication, or in plain M'ords by bodily de- 

 vouring them.* The sole alternative here would be, that the formative 

 influences of the chromatic germs is due to an inscrutable, wholly magi- 

 cal power, by which they determine the structural differentiations by 

 their mere presence and contact. To endow in this manner mere hypo- 

 thetical beings with an all-efficient, utterly mysterious power is clearly 

 to beg the entire question. 



As early as 1861 Lionel Beal advanced a nuclear theory of structural 

 formation, and bravely drew its consistent conclusions. Eelying on 

 tincture of carmine as his principal means of research, he came to look 

 upon all somatic structure as formed of lifeless substance secreted and 

 fabricated by nuclear plasm as exclusive life-bearer and formative agent. 

 And he did not shrink to declare even muscle and nerve to be such life- 

 less fabricates. This monstrous conclusion proves once more to what 

 extreme positions false premises will blindly drive, not only conceptual 

 philosophers, but also close observers of natural phenomena. 



The refutation of the nuclear germ-plasm theory flows, indeed, 

 directly from the nature of the living substance, and its visible vital 

 manifestations. Yet, despite all these weighty considerations, based on 

 actual facts, if the nuclear head of the spermatozoon can be proved to 

 be the real and exclusive bearer of the male characteristics, then no 

 ever so plausible an array of objections could invalidate the conclusion, 

 that- it is after all the nuclear plasm which is endowed with specific 

 formative powers, governing and directing ontogenetic evolution. 



Highly instructive observations of Boveri, and also of Wilson and 

 Mathews, confirmed by many other investigators, prove that it is not the 

 nuclear head of the spermatozoon which is the real bearer of the forma- 

 tive potencies, but its medial portion known to be of non-nuclear origin y 

 and import. As early as 1888 Boveri** described an occurrence that took 

 place in an egg of Echinus, which of itself affords strong evidence that 

 the non-nuclear, medial part of the spermatozoon is its real actively 

 formative constituent. Here the medial part, in which the two cen- 

 trosomes had formed, became completely severed from the nuclear head, 

 proceeding with the astropheres far in advance on its course into the 

 interior of the egg. And though no union of the spermatic nucleus 

 with the nucleus of the egg occurred, the segmentation of the egg-plasm 

 began to take its normal course. The spermatic nucleus, which event- 



*See "Molecular Theories of Organic Reproduction,'' Pro. Texas Acad. Sci- 

 ence, 1895. 



**"ZelIenstudien," January, 1888, "Uber Partielle BeliucUtung Sitz, Ber. 

 Ges-Morph. Pliys. B 4, Miinchen. 



