119 



another^ as usual. We will not discuss further the question 

 (128) aB t» whether giant cells are to be classed with hypertro- 

 phies or hyperplasias, hut will speaJ^: of them here as a con- 

 nocting link betvj'een the two. 



Only those hypertrophies can become raulti- nuclear 

 giant cells, in r'hioh the increase in cell volume is not 

 produced predominantly or oxclut.ivel>' by \;all growth and ab- 

 sorption of v/ater, but is connected .-ith an abundant in- 

 crease of the cytoplasmic content. In hypertrophies of 

 the firet Irind; for instance, in bark excrescences, I know 

 of only uni-cellular forms. It does not seem impossible that 

 in these or similar hypertrophies, iurther investigations 

 will be ablo to prove phenomena of degeneration and decay of 

 the nucleus, Hov;ever, increase of the nuclear substance 

 and division of the nuJ&leus in one of tv/o knov;n v;ays (karyo- 

 kenesis and aaitosis) v/ill undoubtedly remain restricted 

 to thoso hypertrophies, whose cytoplasm is abundantly in- 

 creased. Accordingly, giant cells occur predominantly in 

 f alls , On the other hand, it is necessary to call atten- 

 ion again to many gall-hypertrophies in ^v7hich in fact very 

 abundant cytoplasmic increase occurs, but no nuclear division. 



(129) Most frequently observed and most exactly investi- 

 gated are the giant cells of the nematode galls (produced 

 by Heterodera) occurring on very different host plants and 

 showing every\'/herG a similar inner structurg (Coleus, Circaea, 

 Plantago, Beta, Daucus, Gucomis, Saccharum) « 



1. At the first glance, it may seem forced to discuss in 

 two different places the abnormal multi-nuclear cells, Wliich 

 as is well known, are formed in animal and human bodies through 

 different causes. In the cases gathered together in the first 

 section (the simplest cases), the r'lulti-nuclear condition of 

 the cells is caused by the fact that ^rpvjth and nuclear di- 

 vision are continued normall y, the formation of cross-wa,13.s 

 being omitted abnorraally. As remarked above, it was possible 

 to justify the conception that giant cells of this kind re- 

 present "arrested development" , in v/hich the process of cross- 

 wall formation is completely or partially "arrested". In the 

 other kind of giant cells, they have the character of unmis- 

 takable hypertrophies; the coll is incited to a bnormal growth, 

 ' and the nuclei to division, \;ithOut ohe simultaneous fulxill- 

 ing of the conditions necessarjr for division of the cytoplas- 

 mic body and for the formation of oross-v/alls, This concep- 

 tion is possibly better suited to explain the processes en- 

 acted in the plant body, in the formation of giant cells, 

 than is Ribbert's assumption tbat in the abnormally enlarging 

 <jells, "the injured protoplasm was unable to divide, v/hile th&. 

 nuclei had suffered let's"'. (Lehrb. d, allgem. Tathologie u, 

 d, allg. path. Anat., 1901, p. 198), 



3. According to the statements of the following authors:- 

 !I!reub,QuelQu. mots, s.l, effets du parasitisms de I'Heterodera 

 javanica d.l, racjjnes de la canne a sucre.Ann. Jard, Buitenzorg. 

 1887, T. VI, p. 93. Suillemin and Legrain.SjTiibiose de l«Heterodera 

 radicicola avec l.pl. cultivees au Sahara. C.R.Aca'i.Sc. Paris 

 1894, I.OZVIII,p, 549. Molliard, Sur quelau caracteres histo- 

 log. des cocldies prod, par iTHeterodera raAicicola. Bev.gen, 

 Bot. 1900,2. XII, p, 157.a?ischler,U"eb, Heterodera-Gallen an 

 d. Ti^urzeln.v. Circaea lutetiana L.Ber. d^D.Bot.Ges. 1901, 

 Bd, XIX, p. 95. 



