408 Schmidt-Nielsen, Autolytische Vorgange in gesalzenen Heringen. 



complexity, the process is simplicity itself, the simplest kind of con- 

 tinuity conceivable. 



On the Circle of Life revolves the epicycle of the germ-cells. The 

 circumference of the former is filled in by an uninterrupted succession 

 of such epicycles. The constant sequence of these is the rhythm of 

 reproduction, the gamut of Life. 



Fig. 1. Diagram of the life-cycle of the skate, Raja batis, illu- 

 strating the union of egg and sperm, E and S, to form the zygote Z, 

 the origin of the phorozoou, or larva, or asexual generation, the ger- 

 minal track from Z to U. K. Z., which is the primitive germ-cell, The 

 division of the primitive germ-cell is carried to six mitoses, giving 64 

 primary germ-cells, P. G. C., instead of the full number of nine 

 divisions in a female skate, yielding 512 primary germ cells. Diagram- 

 matically the evolution of one primary germ-cell, the 37 tb, is depicted 

 as forming the embryo or gametozoon. To complete the track of 

 heredity from generation to generation through the morphological con- 

 tinuity of the germ-cells, to the 55th primary germ-cell a diagram of 

 oogeuesis with the formation of male-and female-eggs, and of sperma- 

 togeuesis (as in Paludina after Meves 1 work) to the 20th germ-cell have 

 been added. In the latter the formation of the ordinary spermatozoa 

 H. S. and of the non -functional wormlike ones, W. S. are shown. 



Fig. 2. A portion of E. B. Wilson's diagram of the egg-cleavage 

 of Nereis. 



Fig. 3. The egg-cleavage of Nereis, depicted in fig. 2, represented 

 after the fashion of fig. 1. 



Autolytische Vorgange in gesalzenen Heringen. 

 Von Sigval Schmidt-Nielsen (Bergen). 



Vortrag gehalten in der biol. Gesellschaft zu Christiania am 18. Februar 1902. 



M. H. Bei einer fruheren Gelegeuheit habe ich ihnen mitteilen 

 kijnnen, dass beim Reifen der gepokelteu Heringe eiue Reihe von 

 Spaltuugsprozessen enzymatischer Natur statthaben 1 ). 



larval skin of an Amphibian : it is by no means a new idea to the writer, that 

 the trophoblast represents the whole or the greater part of the asexual gene- 

 ration in mammals. The single clear cell in the sac in Tupaja must be the 

 primitive germ -cell, which must give rise not only to the embryo, but also to 

 the sexual products, or it must become the primitive germ-cell after one or 

 two additional mitoses. It may be regarded as eloquent testimony of the cor- 

 rectness of my conclusions, that in Tupaja Hub r edit should have found 

 the very things, which might have been postulated. 



1) S. Schmidt-Nielsen: Beitrag zur Biologie der marinen 

 Bakterien. Diese Zeitschrift Bd. XXI, Nr. 3, 1901. 



