2 „ 3 The Lesson of the Unnuckated Cell. [May, 
aft „ coniugation, they are at first rapid, then follow at 
tnereasT intervals, and would prove that we have here 
true senescence, with its sequel natural death, or the end of 
th Weisman’s first intimation was an address delivered before 
the German Naturforscher Versammlung, September, 1881. 
He assumes that propagation by simple divrsion may go o 
for ever:* he does not consider whether the cells lorm 
cycles and whether these need be renewed— so misses the 
real problem ; he is enchained by a mystical idea of indiv - 
duality anT reasons as if this rendered direft comparisons 
legitimate between things essentially d ^ ffe ^ t ^^f^ ua 1 J a dog 
individual protozoon is comparable to an individual dog. 
Butschli propounds the hypothesis of a lebensferment, conti 
mmfly resumed in the Protozoa, which thus is potent ally 
immortal ; he also fails to grasp the true idea whether they 
form senescent cycles. Cholodowsky assumes natural death 
is restrifted to multicellular animals, but overlooks the on y 
possible homologues among Protozoa. Goette made an ad- 
vance beyond his predecessors ; he attempted to show tha 
Sere is a death common to all organisms; he concludes 
that death and reproduaion are intimately connected. O . 
Minot savs he appears vague and obscure, and to many 
Ws views y he cannot assent) Now if death and reproduaion 
are intimately conneaed, each cycle before it is completely 
exhausted must produce the initials of new cycles ; hence 
the conneaion in time between maturity, or the approach o 
death, and sexual reproduaion. Hence he arrives at the 
* <« Renrodudtion essentially consists in the separation of a portion of an 
OI h S * m v ^it' or i gi n S ’ ’ 1 he^i mple s t Sade s °occ u r 'among thTproTozoa, which 
(3) spore formation *®^ r ° equenC e . of a process known as conjugation, 
subsequently to or m conseq 1 permanen t fusion of two or more ind.vi- 
which consists in the temp . { F d tl f any suc h previous conjugation 
duals, or spontaneously, . mdepeMly o, any s u ' imply the 
(.; Comparative E-nbrycdo|y Bu. > he n0cleus when present, 
division oi the organism miu r „ l( g es ;,jes single fission 
becoming divided simultaneously with the body. f h es pl Ui f t where 
larger is preceded by a H^ nart ofthe parent form is removed. Both these 
tion of the bud no essen lead to the formations of colonies.” Spore forma- 
P . r< ° C ‘ u SrSot eTsen™ ally differ from that by multiple fission. It consists in 
he breaking up of the organisms into a number (usually very considerable) of 
nortions etch of which eventually develops into an organism Idee the parent 
form.” ‘‘The two processes may co-exist in a single form, .g., 
flagellate monad of Drysdale and Dallinger (lb., p. 6). 
