EXPERIMENTS WITH THE PEACH ORGANISM. 63 



thing and just like those colonies in plates made from A^ and B^. 

 The surface colonies are round, smooth, wet-shining, white, rounded 

 up from the margins, uniform in structure, except a little paler 

 toward the edge, which is sharp. They have darker centers corre- 

 sponding to the buried colonies from which they arose. So far as 

 can be seen under the hand lens they have a uniform very fine 

 granular structure. The largest of these colonies is 5 mm. in diameter 

 and the smallest is 1.5 mm. The buried ones are elliptical, pointed, 

 like those already described. 



(Cj) Needle inoculation: This contains 10 colonies, all of which are 

 alike and evidently the same organism as in A^ and Bj. The largest 

 surface colony is 6 mm. in diameter and the smallest one is about 

 1.3 mm. In their internal structure and their general elevation 

 above the surface the colonies are precisely like those already 

 described. 



(Cj) Contains about a dozen colonies (thin, wide expansions), none 

 of which appear to be like those already described. Most of them 

 have lobed margins and are clearly some other organism. Probably 

 infected in pouring. - 



(Cj) Needle inoculation: Contains one colony, which appears to be 

 of the right sort. 



The structure of the colonies in these plates under the miscroscope 

 (Zeiss 16 mm. and No. 12 ocular) is precisely that of the daisy organ- 

 ism which I have just examined. 



August 10: Photographs were made of Nos. 10 and 17 (PI. XXV, 

 fig. C.) 



January 27, 1908: Alcoholic material was preserved and photos 

 were made. Plates were also then poured from two of the knots. 



February 3: The results obtained from the plates (seventh day) 

 were as follows : (1) The plates from one knot were discarded because 

 they contained yellow and pink colonies, i. e., saprophytes; (2) the 

 set of plates from the other knot contained yellow colonies and white 

 ones. The latter were most numerous and looked like what was 

 inserted. In a very thinly sown plate the largest surface colonies 

 were 8 mm. in diameter. They were perfectly circular, smooth, wet- 

 shining, with sharp margins. The colonies were rather dense and 

 nearly homogeneous to the naked eye, but under the hand lens they 

 were seen to consist of a dense buried central spindle ringed by a 

 clearer space, which was surrounded by a denser zone followed by 

 a marginal clear zone. None of the zones were very sharply defined. 

 The colonies were pure white, i. e., there was no yellow, pink, or 

 greenish in them. In plates containing about 150 colonies the sur- 

 face ones were circular, white, wet-shining, smooth, and rather dense, 

 being 2 to 4 mm. in diameter. The buried colonies were spindle 



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