YEAST FERMENT: FUNGUS INFECTION. 189 



calamities. Nature uses always to attaiu its purposes the most simple and the most 

 effectual ways; therefore it is always the safest way to follow nature. 



Beer mash or diluted yeast should be aj) plied either with a syringe or with a 

 sprinkler ; and the fact that infested insects poison others with which they come in 

 contact will he a great help. Of course it will be impossible to destroy all insects, 

 but a certain limit to calamities could be attained, and I think that is all that could 

 reasonably be expected. In greenhouses the result would probably justify very well 

 a trial, and on currant worms and potato bugs the experiment would not be a difficult 

 one, as the larvae of both insects live upon the leaves, which can easily be sprinkled. 

 But it seems to me more important to make the trial with the Colorado grasshopper. 

 I should recommend to iufestthe newly-hatched brood, which live always together in 

 great numbers, and I should recommend also to bring the poison if possible in contact 

 with the eggs in the egg-hdles to arrive at the same results, which were so fatal to 

 Mr. Trouvelot's silk raising. After all the remedy proposed is very cheap, is every- 

 where to be had or easily to be prepared, has the great advantage of not being obnox- 

 ious to man or domestic animals, and if successful would be really a benefit to man- 

 kind. Nevertheless I should not be astonished at all if the first trial with this rem- 

 edy would not be very successful, even a failure. The quantity to be applied and 

 the manner of the application can only be known by experiment, but I am sure that 

 it will not be difficult to find out the right method. I myself have more confidence 

 in the proposed remedy, since it is neither an hypothesis nor a guess-work, but simply 

 the application of true and well-observed facts. I hear the question. When all this 

 has been known for so long a time, why was it not used long ago ? But is that not 

 true for many not to say for all discoveries ? Most of them are iike the famous Colum- 

 bus egg. 



It will be seen that Dr. Hagen attaches little importauce to the pres- 

 ent opinion and judgment of mycologists as to the non-identity of the 

 several fungi alluded to. We have corresponded with some of the lead- 

 ing cryi)togamists of this country on this subject, and they are quite 

 unanimous in the opinion that there is no one "of the least reputation," 

 to use Professor Farlow's words, who admits that there is an^^ connec- 

 tion between the fly fungus, known as Umpusa muscce but belonging to 

 the genus Saprolegnia, and the yeast fungus, Saccharomyces cerevisice. 

 It is to be regretted, also, that more precision has not been used by 

 Dr. Hagen in referring to these fungi, for the "common mold known 

 to everybody" is most vague, since many diiferent species of mold are 

 recognized by specialists, while " a small water-plant, known only to 

 professional botanists," is such an indefinite expression as to inspire 

 little confidence in the thoroughness of Dr. Bail's experiments. Leav- 

 ing to the specialist, however, the question as to the kind of relation 

 existing between the lower forms of fungi intended to be referred to by 

 Dr. Hagen, we felt that the suggestion coming from so eminent an 

 entomologist was well worthy of practical trial. We took occasion, 

 therefore, to experiment with beer mash by spraying and sprinkling 

 it upon various plants that were to be fed in our vivaria to Lepidop- 

 terous larvae. The principal larvse thus experimented with were of 

 Fapilio asterias, Danais arcMppus, and Fieris rapw. The results gave 

 no encouragement to the hope that anything practical would result 

 from the proposed remedy. The larvae fed with equal avidity and went 

 through their transformations as well as the same species had done on 



