SYMBIOLOGY THE BIOLOGICAL RELATIONSHIPS OF ORGANISMS 121 



try is more advanced. Certain text-books still persist in naming and 

 tabulating the physical properties of the cytoplasm; for example stating 

 that it is viscid, stringy, slimy, tenaceous, semi-liquid, semi-solid, color- 

 less, etc., etc. It may be recalled that so eminent an investigator~as~ 

 Biitschli described plasm a " Wabenartig;" others that it was fibrillated, 

 or granular^etc. 



It may be recalled that Caspar Wolff advanced the theory of epigenesis 

 or the development of individual characteristics through environment, 

 after the union of the gametes or reproductive cells. Wolff may therefore 

 be considered as the biological champion of the believers in the formation of 

 character through environmental influence. In 1892 Weismann formu- 

 lated his epochmaking theory regarding the continuity of the germ plasm, 

 of the pre-f ormation and the pre-de termination of the physical, mental and 

 moral traits of the individual which were supposed to be held or bound 

 within the reproductive cells. An attempt was made to draw a sharp line 

 between the germ cells or reproductive cells and the other body cells or 

 the so-called somatic cells. It is notable that the major theoretical deduc- 

 tions of Weismann have in the main been proven correct in the light of 

 subsequent cytologic and embryologic investigations. 



Various theories were advanced with a view to explaining the mechan- 

 ism of the transmission, from cell to cell and from individual to individual 

 of the inherent or hereditary properties and characteristics of the cell and 

 of the individual. Darwin very ingeniously assumed the existence of 

 biologic molecules which he called gemmules. It was supposed that each 

 and every cell possessed the biological properties of every other cell of the 

 body, represented by the gemmules. Thus it was assumed that a kinetic 

 secreting cell of a gland for example, was also a potential nerve cell; or, 

 that any somatic cell might also be a potential germ cell. De Vries fol- 

 lowed out a similar line of reasoning in his theory of pangenesis in which he 

 suggested that the physical carriers of the hereditary qualities of the cell 

 were the theoretically assumed pangenes which are to be compared to the 

 gemmules of Darwin. Naegeli advanced the micellar theory in which it was 

 assumed that certain biologic molecules and aggregates of such molecules 

 (the micellae and the pleons) directed or controlled the growth of the cell 

 and all other cell activities. Weismann suggested that the hereditary 

 properties of the germ plasm resided in the idants (composed of ids) 

 which were also theoretically assumed to be biologic molecular bodies, 

 comparable to the gemmules of Darwin and the pangenes of de Vries. 

 The structure of the cell and its many constituents received attention, 

 more especially the nucleus which was and still is believed to be the essen- 

 tial part of both the germ cells and the somatic cells, in the animal as well 

 as in the vegetable organism. The chromatin bodies of the nucleus 



