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MONOGRAPH OF THE LABOULBENIACE2E. 



the Saprolegnise," but seems to be an encysted condition of some protozoan or other 

 animal organism, is also not infrequently found on water beetles. 



The collection of Laboulbmiacece involves little more than the collection of a sufficient 

 number of the proper hosts, although their presence on the latter is not always easy 

 to ascertain in case of the smaller forms. In so far as concerns the collection of hosts, 

 my own experience, which is not that of a skilled entomologist, much less of a coleop- 

 terist, indicates that the most favorable localities in which to search for infested beetles 

 is along the margins of small streams or of ponds. In such situations abundance of 

 hosts may usually be found under stones or sticks, or in rubbish, that may be best 

 shaken over a sheet or other white cloth, on which the insects are readily captured. 

 Traps deposited in such situations, and made by raking together a heap of decaying 

 grass, algse, etc., often yield large numbers of interesting specimens when examined in 

 this way. Many forms may also be obtained by leaving bundles of hay or grass in 

 cultivated ground for a few days and examining them over a sheet. Water beetles 

 are in general best obtained by sweeping the margins of ponds or ditches with a 

 dip net; those bearing Zodiomyces occurring in cool gravel along the margins of 

 brooks, or in cold, wet rubbish which has accumulated on rocks or branches in its bed. 

 Staphylinidge which are either mycophagous or fimicolous have not been found to 

 yield any parasites. Forms of this family most likely to be infested are best obtained 

 by using the two kinds of traps above mentioned. The collection of hibernating 

 specimens by " sifting " seldom yield parasites in good condition. A few hosts may 

 be obtained on flowers : Harpalus pennsylvanicus, for example, which is very commonly 

 infested, is usually found in abundance climbing up the spikes of Ambrosia arlemisice- 

 folia about dusk. 



Laboulbeniaceee may be " cultivated " in the manner above alluded to, by confin- 

 ing infested hosts with such as are free from any parasites ; and this is not a matter of 

 any considerable difficulty, provided that surroundings are furnished which are suited 

 to the habits of the insects employed. If pains are taken to keep these surroundings 

 moist and fresh, the parasites will develop normally ; but if there is not sufficient 

 moisture to allow of a certain amount of condensation on the surface of the hosts, 

 fertilization is apt to be interfered with, and, as a result, one finds a large number of 

 abnormal and undeveloped forms. As a rule, it is more satisfactory and quite as little 

 trouble to obtain specimens that have grown under natural conditions, and little, if 

 any, advantage is to be obtained from such artificial cultivation. 



No attempt has been made to cultivate the spores in artificial nutrient media, and 

 the results which might be looked for from such cultures, even if they should prove 



