2i8 "DISEASES" OF BEER, 



in several parts of Germany both in the spring and in the 

 summer months, that is, at a time when there were still no 

 ripe grapes. 



It is highly probable that the yeast cells which I found 

 were carried into the soil in the previous autumn, when the 

 grapes were ripe and the damaged fruit had given rise to 

 endless generations of such cells. These investigations can, 

 however, naturally not prove with certainty that such was the 

 case. I have proved, however, by direct experiments, that 

 cells of various Saccharomycetes, which were placed in the 

 soil in the month of September, were still living after the 

 expiration of a year, that is, from one fruit-time to the next. 

 My first experiments in this direction are described in the 

 journal of the Carlsberg Laboratory for 1882 (French Resumee, 

 p. 203) ; my later investigations are described in the recent 

 communications mentioned above ; amongst the Saccharo- 

 mycetes there was also a typical wine yeast, which I described 

 in 1883 under the name Sacch. ellipsoideus /., also the disease 

 yeast Sacch. Pastorianus I. 



The fact is thus established that at least some of the true 

 Saccharomycetes can pass the winter in the soil* and, further, 

 that sweet succulent fruits offer a favourable medium for their 

 growth. Nevertheless we do not yet know whether their 

 normal habitat is the soil during the winter and spring, and 

 the fruits mentioned during the summer and autumn. The 

 observations which have hitherto been made do not justify 

 us in drawing this conclusion. Before this can be done, 

 similar experimental proof is required to that furnished by 

 my investigations on the migrations of Sacch. apiculatus ; as 

 stated, I have, however, not yet succeeded in furnishing such 

 proof. From the investigations hitherto carried out we must 

 still admit the possibility that there may be other places in 



* In a paper on this subject (1890) Miiller-Thurgau agrees with the view 

 which I put forward. In one point, however, he has misunderstood me, as shown 

 above, in assuming that in my opinion the dissemination of the yeast cells is 

 effected only through the agency of the wind. 



