g2 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 

 ao-ree 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. 

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

 refer the reader to my former paper. ^ 



weise verdanken die griinen Pflanzen wirklich einer Vereinigung eines farblosen 

 Urganismus niit eiiiem von Chlorophyll gleichmassig thigirten ihren Ursprung." 

 (Schimper : Ueber die Eittwickcliiii^^ dcr C/ilorop/iyll/conwr mid Farbkorper, Bot. 

 Zeit., 41. Jahrg., 1883, pp. 111-112.) Schimper supports this statement by quoting 

 Reinke (Allg. IJotanik, 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 e.xists a close analogy between the nucleus 

 and the chromatophore (see Schmitz, Die CliroDiatophorcn dcr Ali^cn, ISonn, 1SS2, 

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

 iHiisciilairc : coiitribiitio)! <) l^iiidc de F i)iJIammalioH paroichyniatcnse. Annales de 

 rinstitut I'asteur, 6»ie Annce, No. i, Janvier, 1S92, pp. 1-20, Pis. I-III), on the 

 repeated division of the vtusele iiuelei in the debris of degenerating viusele fibres 

 whieh originally constituted a part of their cytoplasm, in the course of muscle 

 degeneration, may be interpreted in the same way as Schimi>er did of Reinke's 

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

 tissue referred to above. 



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

 the well-known ])apers by C'fesa-p:ntz and K. IJrandt. Keli.x le Dantec, in his 

 recent paper, Recherclies sur la sy»ibiose des algues et des protozoaires ( Annales de 

 rinstitut Pasteur, t. VI, No. 3, 1S92), has brought further experimental evidence 

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

 Parama-cium, are the symbiotic Alg?e. I mention these simply Xo 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 tliemselves. 



is. Watase : Jfomology of the Centrosome, Jdi-rnai. ok MoKriiiU.ocv, Vol. VI 1 1, 

 Pt. 2, 1893. ^- l^rauer {Zur Kenntniss der Jlerkunft des Ceulrosomas, liiol. Central- 

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

 in the spermatocyte of Ascaris megaloeephala, variety uniTalens, the centrosome 



