AN AQUATIO MYXOMYCETE. 71 



even here it evidently does not consist entirely of that substance, but 

 appears to contain a body (possibly approaching cutin in composition) 

 of some more resistant nature. In most cases the spores are so nearly 

 smooth that the extremely fine punctations on their exterior may 

 easily be overlooked or neglected ; but in other examples the fine 

 punctation is quite noticeable, and it seemed to me that these more 

 evidently marked spores were smaller than the average size, though 

 no differences could be detected in their behaviour. They certainly 

 germinate as readily as do the smoother spores, and behave in exactly 

 the same manner during the process. But, as I shall show directly, 

 there are much greater variations in the size of the spores than these, 

 none of which seem to affect the purpose or behaviour of the spore in 

 the slightest degree. 



Each normally ripe spore contains a quantity of very pale translucent 

 protoplasm in or near the centre of which is a paler and brighter round 

 spot : this is the nucleus shining through the hyaline protoplasm. The 

 nucleus is particularly clear at the moment when germination com- 

 mences (fig. 11, 14), but can always be detected in the resting con- 

 ditions, and also, as will appear subsequently, in other conditions of 

 the contents of the spore. 



With respect to the other varieties of spore referred to above, these 

 are much rarer than what I have described as the normal form. The 

 specimens drawn in fig. 13, however, all came from the same sporan- 

 gium: they are clearly of the nature of double or triple, &c, giant 

 spores, or are malformed specimens, the ripening of which is perhaps 

 completed before the protoplasm has finished dividing up in the young 

 sporangium. In some cases it is almost certain that they simply result 

 from an imperfect separation of the formative masses set apart for the 

 production of spores : an assumption which is supported by the fact 

 that these malformed or giant spores (or complexes of spores) germi- 

 nate quite normally, simply giving rise to a larger number of indi- 

 vidual myxamoebse than do the perfectly isolated spherical spores, 

 selected, on account of their being the more common, as the typical 

 spores. Such abnormal spores are by no means confined to this Myxo- 

 mycete *; apart from the variations in the sizes of the spores of nume- 

 rous species, 2 I have myself observed equally striking differences in the 

 spores of a Myxomycete in the tropics. There can be no doubt, I think, 



1 Cf. De Bary, Vergl. Morphol., der Pilze, die, p. 452. 

 a Zopf, Me Pilz-Thiere, p. 52. 



