LIBRARY 

 NEW YORK 

 BOTANICAL 



GARDEN 



TORREYA 



\'ol. 36 May-June, 1936 No. 3 



The use of Myxomycete plasmodia for instructional purposes 



W. G. Camp 



During the progress of some studies on slime molds the 

 writer has had opportunity to use the plasmodia for purposes 

 of instruction in botany and biology classes. For studying the 

 general characteristics and properties of protoplasm, and proto- 

 plasmic streaming, this material is, in my opinion, very much 

 better than materials which have been commonly utilized for 

 these purposes. This account of the writer's methods of collect- 

 ing, preserving and preparing plasmodia for classroom use is 

 presented with the hope that other teachers may find the in- 

 formation interesting and useful. 



It is well known that the plasmodia of slime molds consist 

 of naked, multinucleate, mobile masses of protoplasm which 

 may be found inhabiting decaying wood and other organic 

 matter. They are found most frequently in the warm seasons 

 and in very moist or wet habitats. Those which inhabit rotting 

 wood are usually found only in the interior of the wood w^hile 

 they are vegetating actively. Usually they emerge only at the 

 time of fructifying. The plasmodia of many of the most common 

 and widely distributed species are either pink or yellow and the 

 fact that they are rather highly colored facilitates finding them 

 on their natural substrata. 



In collecting plasmodia it is well to be provided with a 

 collecting case or vessel in which pieces of moist, rotten wood 

 can be carried without danger of excessive drying. The ordinary 

 vasculum serves the purpose very w'ell. In addition to a collect- 

 ing case, a hand-axe or some similar tool, with which decaying 

 logs and stumps can be cut and broken, will be very useful. The 

 writer has found plasmodia most frequently by examining the 

 interior of stumps and logs located so that they are partially 



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