586 A. E. HILTON ON THE CULTIVATION OF PLASMODIA. 



the fundamental protoplasm. Again I found that the answer 

 to the question was in the affirmative, but with certain reserva- 

 tions. On February 19th last a plasmodium of B. utricularis- 

 was started by reviving a fragment of sclerotium, and this I 

 treated, throughout the whole course of its development, with 

 nothing but bread and water, and the chemical solution, in- 

 cluding calcium phosphate, which I added at Mr. Grundy's, 

 suggestion, with a view to supplying the lime usually found in 

 the sporangia of Mycetozoa classified as Calcarineae. For some 

 weeks, owing to low temperatures, growth was slow, but on the 

 weather becoming warmer, it increased considerably, and finally 

 on May 5th, when the atmosphere became close, with a thunder- 

 storm impending, the plasmodium changed into a quantity of 

 sporangia. 



There are, however, striking differences between these spor- 

 angia and those produced in natural conditions. The shape is 

 similar, but instead of being of the usual cinereous hue, they are 

 mostly a dull purple-black ; others being of a cinnamon-brown 

 colour, and some of a pale biscuit tint. All are sprinkled with 

 white crystalline particles. The sporangium walls, usually 

 very thin and fragile, are hard, thick, and chippy ; and there is 

 no distinguishable capillitium. Stranger still, the sporangia 

 are only about half the ordinary diameter ; in other words, 

 about one- eighth of the usual size. The spores, generally bright 

 brown and spinulose, are smooth and almost colourless ; but 

 they are of the usual dimensions, if not, on the average, slightly 

 larger, and in other respects appear to be perfectly normal. 



The characters on which the classification is based are thus 

 altered in nearly every particular ; the only permanent feature, 

 if there is one, being the specific spore-plasm. The result shows 

 what remarkable powers of adaptation the plasm possesses, 

 how precarious the present basis of classification really is, and 

 how impossible it is to define a species without a deeper know- 

 ledge than we yet possess of the specific character of the plasm 

 on which all the activities of physical life depend. 



Journ. Quckett Microscopical Club, Ser. 2, Vol. XII., No. 77, November 1915 



