230 SOME PROBLEMS OF CELL-ORGANIZATION 



rows without loss of their individuality. 1 In a later paper on the 

 sea-urchin ('95) this view is somewhat modified by the admission that 

 in this case the archoplasm may not pre-exist as formed material, but 

 that the rays and fibres may be a new formation, crystallizing, as it 

 were, out of the protoplasm about the centrosome as a centre, 2 but 

 having no organic relation with the general reticulum. 



Strong evidence against the archoplasm-theory has been brought 

 forward by many investigators, and I believe it to be in principle 

 untenable. Nearly all recent workers have accepted in one form or 

 another the early view of Biitschli, Klein, and Van Beneden that the 

 astral rays and spindle-fibres, and hence the attraction-sphere, arise 

 through a morphological rearrangement of the pre-existing protoplas- 

 mic network, under the influence of the centrosome. Although this 

 view may be traced back to the early work of Fol ('73) and Auerbach 

 ('74), it was first clearly formulated by Biitschli ('76), who regarded 

 the aster as the optical expression of a peculiar physico-chemical 

 alteration of the protoplasm primarily caused by diffusion-currents 

 converging to the central area of the aster. 3 An essentially similar 

 view is maintained jn Biitschli's recent great work on protoplasm, 4 

 the astral " rays " being regarded as nothing more than the meshes 

 of an alveolar structure arranged radially about the centrosome (Fig. 

 8, B). The fibrous appearance of the astral rays is an optical delu- 

 sion, for they are not fibres, but flat lamellae forming the walls of 

 elongated closed chambers. This view has more recently been urged 

 by Reinke and Eismond. 



The same general conception of the aster is adopted by most of 

 those who accept the fibrillar or reticular theory of protoplasm, the 

 astral rays and spindle-fibres being regarded as actual fibres forming 

 part of the general network. One of the first to frame such a con- 

 ception was Klein ('78), who regarded the aster as due to " a radiar 

 arrangement of what corresponds to the cell-substance," the latter 

 being described as having a fibrillar character. 5 The same view is 

 advocated by Van Beneden in 1883. With Klein, Heitzman, and 

 Frommann he accepted the view that the intra-nuclear and extra- 

 nuclear networks were organically connected, and maintained that 

 the spindle-fibres arose from both. 6 "The star-like rays of the asters 

 are nothing but local differentiations of the protoplasmic network. 7 

 . . . In my opinion the appearance of the attraction-spheres, the 



I '88, 2, p. 80. 2 I.e., p. 40. 



3 For a very careful review of the early views on this subject, see Mark, JAinax, 1881. 



4 '92, 2, pp. 158-169. 



5 It is interesting to note that in the same place Klein anticipated the theory of fibrillar 

 contractility, both the nuclear and the cytoplasmic reticulum being regarded as contractile 

 (/.*., p. 417). 



II ' 8 3> !> 592. ~ '83, p. 576. 



