14 ARKIV FÖR BOTANIK. BAND 1*2. N:0 9. 



chromatin presumably travels to the periphery through radi- 

 ating linin-filaments. This is in perfect accordance with my 

 investigations. 



It is presumably due to the description by Nawaschin 

 and Prowazek of the total disappearance of the nuclei that 

 the concept is still in existence that the nuclei are resolved, 

 and that eventually fresh ones are formed. — As regards 

 Spongospora a similar solution of the nuclei has lately been 

 described (Osborn-^). 



As regards the form of the mature spores it must be 

 remarked that they are furnished with a collar-formed swel- 

 ling of the apex (see fig. — ). This has not been mentioned 

 by the named authors. 



Ligniera Juiici (Schw^^rtz) Maire et Tison. 



In the year 1910 Schwartz-'^ found a Plasmodiophoracea 

 on roots of Jiinciis bufonius, J. articulatus and J . lampro- 

 carpus, and he shortly treats its biology, which is interesting 

 in this respect that in several ways it differs from Sorosphaera 

 Veronicae. He points out that the infection of the host-plant 

 takes place in this w^ay that an amoeba penetrates into a 

 root-hair and from there travels to the root itself, dividing 

 on the road. He does not, however, treat this travelling in 

 greater detail. From his description and illustrations we, 

 however, come to the conclusion that the amoebae are really 

 able to penetrate through the cell-walls which they meet on 

 their way. Another characteristic is, that the fungus does 

 not produce hypertrophy or formation of gigantic cells like 

 Sorosphaera Veronicae and Plasmodiophora Brassicae. On the 

 contrary we do not observe any unusual features in macro- 

 scopical respect in the infected plants. The infected cells 

 keep their normal seize and normal nucleus. The spore- 

 aggregations of this species are often not at all spherical, 

 and Schwartz is of opinion that the reason hereof is, that 

 the cells do not become hypertrophied; in the small cortical 

 cells of the root there is no room for the large hollow spheres, 

 hence the spores are forced to arrange themselves in indif- 

 ferent congregations. — It may, however, be questionable 

 whether the space-conditions are indeed the real »cause». — 

 On account of this species not producing hypertrophy Maire 



