118 



. fungus^hypjae in the formation of lichens.^ Gamaleia^, 



Mat^pschita (loc. cit.) and others ohfcerved "involution- 



(127) forms in yoast . Schostalxowitsch^ gathered sausage-like or 

 iobated spores from Mucor -proliferus . 



The question whether the deformations here described 

 are connected in all cases with an injury of the cells in*- 

 fected . i, e., in the organisms here concerned, -may riot "be 

 decided definitely. In any case the injury is often only 

 slight and is felt only temporarily* In many cases indeed 

 root-hairs and fungus^hyphae continue their growth normally 

 after th© formation of some distended places, intumescences, 

 In extreme cases the injury is unmistakable. In involution-*- 

 forms of "bacteria and in the deformations of Muoor mycelium 

 described by Klebs^ the cells gradually lose their cyto- 

 plasmic contents and literally £;row until they die,- cohh- 

 parabiy to -ttie cells of the hyperhydrio tissue, discussed 

 above, Thus in these too we may speak of a decided kata- 

 plastic hypertro-ph y. I 



7^ Multinuclear Giant Cells « 



Multinuclear cells have already been mentioned. If 

 cells of Spirogyra filaments, or the like, continue their 

 growth normally, if the nuclei divide regularly but for some 

 reason the formation of oross-^walls becomes impossible, i& 

 then results in multinuclear cells, (See above p. 69) . In 

 the following, cases are to be described, in v/hich cells of 

 any kind are stimulated to ab norm al grov;thy and their nuclei 

 to division, without the formation of cross-walls. We can 

 desig-nate cells of the latter kind as transitions between 

 hypertrophies and hyperplasias* To this must be added the 

 fact that many giant cells subsequently form septa, after 

 repeated nuclear division, just as we could prove above for 

 giant cells produced by a continuation of normal grovrth-ac- 

 tivity. It must be added further that, simultaneously with 

 the production of multinuclear giant cells, abnormal cell 

 divisions take place in adjacent tissues » by which nuclear 

 division and cross-wall formation are related to one 



1. Stahl, Beitr. z, EntwickelungBgesch. d. Flechten, 1877, 

 Heft 2;. Compare also Lagerheim, Ueb, eine durch d. Einwirk- 

 ungv. Pi^-zhyphen entstehende Varietat. v, Stichococcus bac- 

 illaris Kag. Flora, 1888, Bdp LXXI, p, 61. Bonnier (Germin- 

 ation d, lichens s, 1. protonemas d. mousses. Hev. gen» de 

 Bot., 1889, T. I. p. 165). obtained irregular, swollen cell 

 forms on the moss protonema plants ooloniaed by fungi. 



2, Quoted in Jahresber f. Tierchemie, Bd. XXVI, p. 923. 



„ 3. Einige Versuche {ib. d. Abhangigkeit d. M. pr* |v. d, 

 auss. Beding, Flora, 1897, Bd. LXXXIV, p. 88, 



