42 THE ARRANGEMENT OF THE 



To obviate the suspicion that these appearances were produced, at least 

 in part, artificially, fresh mould was examined in an indifferent medium, such 

 as bichromate of potash, and a complete correspondence with what chloride 

 of gold showed was found, although in a less marked degree ; so that I would 



FIG. 10. MILDEW STAINED WITH ONE-HALF PER CENT. SOLUTION 

 OF CHLORIDE OF GOLD. 



<ia, threads of mycelium ; b b, liyphae ; c c, conidia ; d d, chains of conidia. Granular buds are 

 visible on all hyphae and chains of conidia, while buds are missing altogether on thick- 

 walled conidia, cc. At ee conical buds or projections are present, the thicker ends of 

 which are compact and stained dark violet, while , their stems appear light. Magnified 

 1200 diameters. 



assert that only those who have studied the chloride of gold preparation 

 previously will find the fine threads connecting the granules in a fresh 

 preparation. 



I have also examined several kinds of oidium, of which the close rela- 

 tionship among each other, as well as with the spores of mildew, has been 

 repeatedly demonstrated by other observers. 



The structure of beer-yeast is identical, both in the fresh condition and 

 after staining with chloride of gold, only in the latter case the appearances 

 are more marked than in the former. In fresh preparations, free granules of 

 various sizes are recognized, of which some are at the limit of the visible, 

 even with an amplification of 1200, and groups composed of numerous 

 homogeneous, yellowish, shining, apparently structureless granules, which 

 are connected with each other by extremely delicate threads. The latter 

 are not yellow, but gray. Some granules have fine offshoots, the con- 



