THE INFECTION OF ACHLYA WITH VARIOUS MICROORGANISMS 



By Marshall A. Barber 

 (From the Biological Laboratory, Bureau of Science, Manila, P. I.) 



Three plates 



In a previous paper ^ I described a method of inoculating 

 microorganisms and other substances into the vacuoles or proto- 

 plasm of living cells; and, in a later article,- gave some of the 

 results obtained by such inoculations into fish molds, various 

 algse, and the larvae of a gnat. In this paper essentially the same 

 method of inoculation has been used ; but the host has been grovi^n 

 in pure culture, thus making it possible to add various media 

 or other substances to the culture and to do away with bacteria 

 other than the ones inoculated. 



Achlya, one of the fish molds, was chosen for these experi- 

 ments because of its large filaments and ease of cultivation. 



Pure cultures were easily obtained by the method of single- 

 cell isolation described by me in various publications.* Insects 

 were placed in water containing algse, in the usual manner of 

 obtaining cultures of fish molds. After a crop of zoospores had 

 formed, a mass of them in the resting condition was transferred 

 to a hanging drop. With a fine capillary pipette, single zo- 

 ospores were separated from the mass, freed from bacteria by 

 successive washings in droplets of sterile water, picked up with 

 a fresh pipette, and each one transferred to a test tube con- 

 taining distilled water plus a small quantity of glucose broth. 

 The whole process of isolation of a series by this method re- 

 quires only a few minutes. Or, a mass of zoospores, partially 

 freed from bacteria, may be deposited in one end of a long hang- 

 ing drop of sterile water. These spores, at first invested with 

 a membrane, burst the membrane within two or three hours 

 and swarm to the other end of the drop. They may be picked 



^Journ. Infect. Dis. (1911), 8, 348. 



'Ibid. (1911), 9, 117. 



' Sci. Bull., Kansas Univ. (1907), 4, 3. Journ. Infect. Dis. (1908), 

 5, 380; (1909), 6, 634. An article describing the method in detail is 

 now in preparation, and will be published in an early number of this 

 Journal. 



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