THE ASEPTIC CULTIVATION OF MYGETOZOA. 49 



tozoa from the Infusoria, Amcebse, and other protozoic forms 

 found in hay infusions. 



The cultures are usually transplanted by means of a sterilised 

 pipette. 



Bacteria are found in all the cultureSj and studies have been 

 made with the view of finding out what effect bacteria have on 

 the growth of Mycetozoa, and what bacteria, if any, are more 

 favorable to their growth. 



It is not the writer's purpose to discuss the influence of the 

 bacteria in this connection, but he will leave it for a future 

 communication. 



The Mycetozoa cultivated. 

 Physarum cinereum. 



This was the first plasmodiura from the air which was culti- 

 vated. It will grow and form plasmodia in water with 2 per 

 cent, milk or in dilute hay infusion. The best cultures are 

 obtained when the hay also is present as described above. 



In all the cultures where sporangia are formed, the plas- 

 modia grew in the fluid and crawled on the side of the flask 

 above the fluid preparatory to the formation of the sporangia. 

 Although the largest plasmodia form in cultures containing 

 hay, yet the sporangia only form on the glass. 



The plasmodia spread out on the glass in the form of a 

 yellowish-white network, consisting of primary trunks from 

 which run branches anastomosing with each other^ the net- 

 work becoming finer as the periphery is approached. At the 

 periphery there is a more or less flattened perforated proto- 

 plasmic plate with a scalloped border. In the cultures not 

 containing hay the principal trunks extend to the water; in 

 cultures containing hay the plasmodia spread out from stems 

 of hay leaning against the side of the flask (fig. 2), and it 

 cannot be determined whether branches extend to the water. 



In the more vigorous cultures the plasmodia are large 

 enough to cover the whole inner surface of the flask above the 

 water, but do not pass to the cotton plug. 



VOL. 41, PART 1. NEW SERIES. U 



