and other Mycetozoa. 
295 
compacted, or composed of stellate crystals loosely combined ; 
it may be scattered in patches and enclosed in a double mem- 
brane, or may be entirely wanting. 
The capillitium may be well developed, composed of stout 
forking threads, or may be of delicate form (a variation shown 
as strikingly in Didymium dubium ), or it may be absent 
altogether, and the spores may vary both in colour and 
dimensions. 
The colour of the membranous wall of the sporangia, as 
well as of the threads of the capillitium, varies widely in 
different fruits of the same stock, and there is often a slight 
though well-marked difference of colour in the plasmodia. 
When these varying characters are seen in the one species 
in which the life-history has been followed through successive 
generations, one is led to anticipate that if methods should be 
discovered for cultivating other kinds which have hitherto 
baffled our endeavours, we should find that many closely allied 
forms which are at present considered as distinct species, may 
be traced to a common parentage in this most variable group. 
The following is a list of species in which I have observed 
the formation of sporangia from the plasmodium, with the 
colour of the latter appended. A large proportion of these 
were obtained by collecting rotting leaves on which plasmodium 
was seen, or betrayed by the peculiar odour attaching to it ; 
they were preserved under bell-jars and frequently supplied 
with fresh rain-water, and, after some weeks of little promise, 
unexpected sporangia would often make their appearance on 
the leaves. 
Species. 
Amaurochaete atra 
Arcyria cinerea 
— ferruginea 
- incarnata 
nutans (buff variety) 
* * nutans (red variety) 
— — punic e a 
Colour of Plasmodium. 
yellowish white. 
greyish white. 
rose. 
white. 
white. 
white. 
white. 
