MAX SCHULTZE. 97 



protoplasm of Von Mohl ought to be credited with a much 

 higher importance, not only for the cell life, but also for the 

 formation of tissues in the animal organism, than it had 

 hitherto been. He rested these opinions on his own observa- 

 tions, and chiefly on the formation of the contractile substance 

 of the muscular fibres of frogs and salamanders from the pro- 

 toplasm of the embryonal muscle cell. Then, touching on 

 Beale, he says "No one who has the development of the 

 general doctrine of tissue formation at heart will deny that the 

 first requisite of progress in this direction is an accurate know- 

 ledge of the individual constituents of the cells, and their part 

 in the development of the tissues. The need of such progress 

 is even felt also in those quarters in which the cell theory has 

 not yet been understood, and among such is to be reckoned the 

 work of Beale" [on the " Simple Tissues," 1861], "which will 

 not meet with the attention it otherwise deserves, because it 

 stands outside the cell theory. Beale's * Germinal Matter' is, it 

 is true, essentially that which we call protoplasm, including 

 also, certainly, the nucleus ; and the ' formed matter/ that 

 which is formed and gives form to the tissues is brought into 

 an essentially correct dependence on the protoplasm. But of 

 cells as elementary parts, or elementary organisms, of nuclei 

 which are distinct from, and yet so necessary to the protoplasm, 

 there is no word. For him the great and inalienable [unveraus- 

 serliche] discovery of the cell is of only historical interest" 

 (p. 3). He then proceeds to state that he gives the protoplasm 

 the same importance in animals as, since Mohl, the botanists 

 have long assigned to it in vegetables. But the membrane is 

 not thereby to be thought of no account, for it is necessary to 

 the formation of rigid structures, for which purpose the proto- 

 plasm is unfitted, from its physical consistence. Although he 

 speaks of the protoplasm as "properly speaking, the living 

 substance of the cell," he does not clearly state that the mem- 

 brane and the tissues are not living, and gives no clear notion 

 of the relation of the cell membrane to tissues. He is still 

 taken up with the demonstration that animal cells, or proto- 

 plasm corpuscles, can exist without a cell membrane, instancing 

 the cells of the Hydra, the Amoeba, the Myxomycetaa, <fcc. 



7 



