42 WHITMAN. [VoL. Il. 
One needs only reverse the case to see the illogical nature of 
the position. Let us suppose that it has been ascertained by 
numerous experiments that the nucleus of an infusorium is in- 
capable of karyokinetic division when separated from the cyto- 
plasm, except in those cases where the division is already in 
progress at the time of separation. Would there be anything 
either in the general rule or in these exceptional cases, from 
which to conclude that the performances of the nucleus are first 
set in motion by some impulse from the cytoplasm? Would 
the incapacity of the nucleus to divide when placed in abnor- 
mal conditions demonstrate its inability to divide autonomically 
under normal conditions? If artificial isolation were found 
insufficient to arrest a series of complex movements already | 
begun in the nucleus, would the death of the nucleus, shortly 
after the completion of these movements, furnish any ground for 
denying that they were automatic? These questions appear to 
present the matter in a just light, and to carry with them their 
own answers. The point would hardly seem to deserve the 
attention given it, were it not for the great importance of 
the question under consideration, and the fact that we are 
dealing with the opinion of a high authority, — an opinion for 
which experimental evidence of a crucial nature is claimed, 
and an opinion fully indorsed by so eminent a thinker as Weis- 
mann. 
Schneider's Experiment. — Schneider’s 24 (p. 509) experiment 
with Thalassicolla, although not affording any decisive evidence 
as to the precise location of the formative power, is yet of some 
interest in this connection. The extracapsular or cortical pro- 
toplasm was removed, leaving the central capsule free. At the 
end of twelve hours the whole surface of the capsule showed 
delicate pseudopodial extensions, and soon after appeared a dis- 
tinct extra-capsular layer (“ matrix” of the pseudopodial rays), 
which gradually grew to normal thickness. The experiment was 
repeated three times in succession on the same individual, and 
each time with the same result. The extra-capsular envelope 
gave no evidence of sharing the regenerative power, but died 
shortly after isolation. This envelope, according to Brandt ?° 
4 Zur Kenntniss des Baues der Radiolarien. AZ#l. Arch. 1867, p. 509. 
© Koloniebildende Radiolarien (Sphaerozoéen). Fauna und Florad es Golfes 
von Neapel. XIII. Monographie, 1885. 
