THE BASIDIA OF PUCCINIA MALVACEARUM 535 



A camera-lucida drawing 

 spores were shot from the 

 sorus in the still air of 

 the compressor cell is 

 shown in Fig. 214. An 

 inspection of the drawing 

 reveals that a large num- 

 ber of spores were shot a 

 distance of 0-5 mm. and 

 some • 6-0 • 75 mm . , and 

 that the maximum dis- 

 tance of discharge (spore 

 on the extreme right) 

 was 0-85 mm. If the 

 spore which had travelled 

 • 85 mm. away from the 

 extreme right edge of the 

 sorus was discharged not 

 from the edge of the 

 sorus but say from 0-15 

 mm. to the left of the 

 edge, its total distance 

 of horizontal projection 

 must have been 1 mm. 



Whilst Fig. 214 was 

 being drawn, a number 

 of basidia were still dis- 

 charging spores. The 

 excretion of a drop of 

 water from the hilum of 

 one of the spores in the 

 course of a few seconds 

 just before the spore was 

 discharged was clearly 

 perceived, although the 

 magnification of the 

 microscope was only 60. 



showing the distance to which the basidio- 



FiG. 215. — Puccinia Malvacearum. Development 

 of curved basidia. A, section through a 

 teleutospore-sorus from a Hollyhock leaf, a 

 few hours after being placed in a damp com- 

 pressor cell. Some of the teleutospores have 

 germinated and have produced curved basidia. 

 The one on the extreme right is developing 

 sterigmata. B, spores with young basidia 

 isolated from A : the basidia are at first 

 straight and become curved only by further 

 growth. C-H, elements isolated from a teleuto- 

 spore-sorus on a leaf of Malva sylvestris. 

 C, D, teleutospores with young curved basidia ; 

 E, a teleutospore with one collapsed basidium 

 which has discharged its spores and one basidium 

 about to develop spores ; F, a basidium be- 

 ginning to develop sterimata ; G, a sterigma 

 beginning to develop its spore ; H, a discharged 

 spore. I, semi-diagrammatic representation of 

 a teleutospore which has produced a curved 

 basidium with the sterigmata and spores on the 

 convex side. The arrows indicate the probable 

 paths of the basidiospores after discharge. 

 Magnification, 293. 



