338 BROOKLYN BOTANIC GARDEN MEMOIRS 



pointed out in the above mentioned paper, that certain smuts (as 

 Doassantia deformans, e. g.) also possess botryose haustoria.^ 



The i8 figures in Plate VIII show fairly clearly the salient features 

 of the cytological structure and development of BotryorJiiza, with the 

 exception of the sexual fusions, which have not as yet been found. 

 Undoubtedly, however, these fusions and the consequent transition 

 from the uninucleate condition initiated in the germinating pro- 

 mycelium to the binucleate condition prevalent in the vegetative 

 mycelium, must take place early in the development of the latter. 



Two hypophyllous sori are shown in Fig. i, the one at the right 

 a very young one pushing through a stoma. The mycelium and 

 hy menial hyphae are seen to be composed of binucleate cells, as is 

 also the case of the young spores. Two of the peculiar botryose haus- 

 toria are shown at the lower portion of the figure, nearly filling the 

 host cells. Fig. 2 shows a portion of the coarse, branched, inter- 

 cellular mycelium, with some its binucleate cells. This mycelium 

 varies from about 5 to 7 ju in diameter. One cell is shown with four 

 nuclei, evidently a result of a recent conjugate division. The con- 

 spicuous thickenings drawn along the edges of the hypha are colored 

 red in the preparation with Flemming's triple stain ; their mode of 

 origin and significance still remain to be solved. 



Figs. 3-7 show five varying views of the large botryose haustoria. 

 The narrow isthmus connecting the enlarged haustorium with the 

 extra-cellular mycelium is clearly shown in each case, as is also the 

 interesting fact that the haustorium, even in those cases in which the 

 host cell is almost entirely filled by it, pushes in as it grows the plasma 

 membrane of the host protoplasm. Strictly speaking, therefore, in 

 no case is the haustorium really inside the host protoplasm. Fig. 3 

 is a section of a young haustorium showing this invagination of the 

 host cytoplasm. Four nuclei of the rust are also shown in this prepara- 

 tion. In Fig. 4 an older haustorium showing its peculiar botryose 

 swellings, has pushed up into an unusually dense mass of host cyto- 

 plasm, now shrunken away from the invaginated haustorium. Figs. 

 5, 6, and 7 show almost equally clearly this phenomenon of invagina- 

 tion of the host cytoplasm. In Fig. 5, particularly, the haustorium is 

 seen to almost fill the host cell. An idea of the large size of the haus- 

 toria may be gained from the fact that while the cells of the leaf of the 

 host Ilippocratea measure from 15 to 20 /x in diameter, those of the 

 fungous haustoria range from about 10 to 14 n in diameter. 



Figs. 8 to 14 show various stages in the formation and germination 

 of the teliospores. Fig. 8 is of a young sporiferous hypha showing two 



' Lutman, B. F. Some contributions to the life history and cytology of the 

 smuts. Trans. Wis. Acad. Sci. 16: 1191-1244. 1910. See his Figs. 44 and 45. 



