222 PROTOPLASM 



movement must have as a postulate " an organisation of th< 

 protoplasm," " a peculiar structure in it, which differs essentially 

 from the aggregate condition of viscid fluid bodies in the faci 

 that the molecules of the protoplasm are capable of being un 

 equally displaced in different directions." Of this allegec 

 postulate of every explanation he makes, however, no use what 

 ever, either in considering the phenomena of the structure, or o 

 the movement of protoplasm; the hypothesis evolved by hin 

 with regard to protoplasmic movement contains no mentioi 

 of it. 



In opposition to these efforts, it must be of special interest t< 

 us that two observers so experienced in physical matters ai 

 Nageli and Schwendener both in 1865 and later in 1877 

 especially point out the "viscid nature " of protoplasm, somewha 

 like mucilage ; it may then, of course, possess an organisation wit] 

 impunity. They derived their proofs chiefly from the flowing 

 together that may frequently be observed in protoplasmic bodies 

 and the behaviour of swarm spores when they happened to fo 

 torn in pieces. 



Briicke's views soon found further defenders. In 187( 

 Hanstein expressed himself to the same effect. It seemed also t< 

 him quite unthinkable that from a fluid substance a structur 

 should have been produced which was organic, and " therefor 

 different in itself." For the rest, his ideas of protoplasm at tha 

 time were rather obscure. He ascribes to it " a soft and plastic 

 and yet viscid and formed and self-forming condition." It wa 

 said to contain besides fluid parts, " soft solid " ones as well ; i 

 was not a substance but an organism. 



But it was Yelten especially who in his works (1873-76 

 tried to collect further proofs for Briicke's conception. For hin 

 also it was an established fact (1873) that protoplasm possesse< 

 in any case a complicated organisation, and was not a homogeneou 

 fluid. But how he really represented the matter to himself i 

 not quite clear. In 1876 he declares that protoplasm is com 

 posed of solid and fluid parts. Thus on p. 138 it is said tha 

 "in protoplasm we have a more or less coherent body, possessing 

 the solid aggregate condition, which last may be temporarily 

 exchanged for that of fluid substance." If the latter limitatioi 

 makes the view first pronounced rather obscure, the following 

 passage (p. 130) adds still further to the obscurity, where it is sai( 

 " that protoplasm contains solid and fluid parts side by side in th< 

 smallest particles of space." Velten's view is partly based upoi 

 structures observed by him (see above, p. 165), partly upon thi 

 peculiarities of the phenomena of streaming. He makes sincen 

 efforts to reconcile with his view the tendency of protoplasm t< 



