322 SOME PROBLEMS OF CELL-ORGANIZATION 



In its original form the archoplasm hypothesis, as stated by Boveri, 

 was developed with reference only to the material of the spindle- 

 fibres and astral rays. Later writers have greatly extended the con- 

 ception on the basis of Boveri's earlier view that archoplasm is a 

 specific form of protoplasm, possessing specially active properties. 

 Strasburger ('92-98), whose views have already been considered in 

 part, believes the protoplasm to consist of, or to show a tendency to 

 differentiate itself into, two distinct substances, namely, a specially 

 active fibrillar kijioplasin and a less active alveolar tropJioplasin. 

 The former gives rise to the mitotic fibrillae, constitutes the periph- 

 eral cell layer, or HautschicJit, from which the membrane arises, 

 forms the substance of the centrosomes, and gives origin to the con- 

 tractile substance of cilia and flagella. The kinoplasm is thus mainly 

 concerned with the motor phenomena of the cell, the trophoplasm 

 with those of nutrition ; and this physiological difference is morpho- 

 logically expressed in the fact that the former has in general a 

 fibrillar structure, the latter an alveolar. Beyond this the two forms 

 of protoplasm show a difference of staining-reaction, the kinoplasmic 

 fibrillae staining deeply with gentian-violet and iron-haematoxylin, 

 while the trophoplasm is but slightly stained. 



Prenant ('98, '99) still further extends the hypothesis, adopting the 

 view that the " ergastoplasmic " (Garnier) fibrillae of gland-cells ^ are 

 equivalent to the kinoplasmic or archoplasmic fibrillae of the mitotic 

 figure, and to the fibrillae of nerve- and muscle-fibres as well. He is 

 thus led to the conception of a dominating or " superior " cytoplasm 

 (including "archoplasm," "kinoplasm," "ergastoplasm"), which arises 

 by differentiation out of the general cytoplasm, plays the leading role 

 in the elaboration of active cell-elements (" cytosomes "), such as 

 mitotic, neural, and glandular fibrillae, and finally, its role accom- 

 plished, may disappear. Under the same category with the foregoing 

 structures are placed the centrosome, attraction-sphere, mid-body, 

 idiozome, Nebenkern, and yolk-nucleus. 



Such a generous expansion of the archoplasm-hypothesis brings it 

 perilously near to a rediictio ad absitrdmn ; for the step is not a great 

 one to the identification of the " superior protoplasm " with the active 

 cell-substance in general, w.hich would render the whole hypothesis 

 superfluous. Physiologically, we can drav/ no definite line of demar- 

 cation between the more and the less active protoplasmic elements, 

 and it may further be doubted whether such a boundary exists even 

 between the latter and the metaplasmic substances.^ It is further 

 quite unjustifiable to infer physiological likeness from similarity in 

 staining-reaction^ or in fibrillar structure. For these reasons the 

 hypothesis of " superior protoplasm " seems one of doubtful utility. 



^ Cf. the pancreas, p. 44. 2 cf. p. 29. 3 q*; p^ -^^^ 



