92 BIOLOGICAL LECTURES. 



the views held by Schmitz, Schimper and others, we have 

 already regarded this structure as an organ totally independent 

 of the colorless protoplasm of the green plant. In regard to 

 the centrosome, aside from its apparent function during the 

 division of the nucleus, we know very little to justify our 

 discussion in the present connection. Personally, I cannot 

 agree with those who place the centrosome in the same category 

 of the permanent cell-organs as the nucleus. On the other 

 hand, I believe that the centrosome is a special form of the 

 cytomicrosome, which exists almost in every part of the cell. 

 For the reason of this homology of the centrosome, I may 

 refer the reader to my former paper. 1 



weise verdanken die grunen Pflanzen wirklich einer Vereinigung ernes farblosen 

 Organismus mit einem von Chlorophyll gleichmassig tingirten ihren Ursprung." 

 (Schimper: Ueber die Entwitkelung der Chloropkyllk$mer mid Farbkorper, Bot. 

 Zeit., 41. Jahrg., 1883, pp. 1 1 i-i 12.) Schimper supports this statement by quoting 

 Reinke (Allg. Botanik, p. 62), who states that the chlorophyll bodies in the 

 decomposing cells of a cucumber attacked by a certain fungus, still continued to 

 grow and multiply. 



In view of the fact that there exists a close analogy between the nucleus 

 and the chromatophore (see Schmitz, Die Chromatophoren de+Algen, I'.onn, 1882, 

 p. 167), the observations by Metschnikoff and Soudakewitch (La phagocytose 

 musculaire ; contribution a I" etude de F inflammation parenchymateuse. Annales de 

 1'Institut Pasteur, 6 me Annee, No. i, Janvier, 1892, pp. 1-20, Pis. I-III), on the 

 repeated division of the muscle nuclei in the debris of degenerating muscle fibres 

 which originally constituted a part of tJteir cvtoplasm, in t/ie course of muscle 

 degeneration, may be interpreted in the same way as Schimper did of Reinke's 

 observation on the behavior of the chlorophyll bodies in the decomposing vegetable 

 tissue referred to above. 



For the view that considers the animal chlorophylls as the veritable Algae, see 

 the well-known papers by Gesa-Kntz and K. Brandt. Felix le Dantec, in his 

 recent paper, Recherches sur la symbiose des algucs et des protozoaires ( Annales de 

 1'Institut Pasteur, t. VI, No. 3, 1892), has brought further experimental evidence 

 in support of the view that the chlorophyll corpuscles in an animal organism as 

 Paramacium, are the symbiotic Algae. I mention these simply to call attention 

 once more to the fact that certain parts of an organism, which were originally 

 considered to be integral elements of the organism, derived by the differentiation 

 of the germ, have been shown to be due, in reality, to a secondary association of 

 two or more different organisms, originally separate and independent, and what 

 we call organs from the physiological side, in such an organism, are in reality 

 organisms by themselves. 



1 S. Watase : Homology of the Centrosome, JOURNAL OF MORPHOLOGY, Vol. VIII, 

 Pt. 2, 1893. A. Brauer (Zur Kenntniss der Herkunft des Centrosomas, Biol. Central- 

 blatt, Bd. XIII, Nr. 9 u. 10, May, 1893), nas recently come to the conclusion that 

 in the spermatocyte of A scar is megalocephala, variety univalens, the centrosome 



