452 MRS. H. L. M, PIXELL-GOODRICH ON 



fairly easily when treated Avith certain reagents, metliyl-green 

 acetic mixture for example. From a young spore undei' these con- 

 ditions the spherule makes its way out as soon as the operculum 

 is raised. Similar bodies have been mentioned as occurring in 

 ma,ny Haplosporidia. In Minchinia the spherule is very large at 

 the stage when the spore coat is nearly completed (figs. 13 & 14), 

 and after this appears to gradually diminish, until in the ripe 

 spore it is generally not to be distinguished at all. Possibly it is 

 composed of some kind of reserve food on which the developing 

 spore can feed as soon as it is cut off from the outer world by the 

 formation of its thick chitinous coat. 



During the deposition of the substance which forms the chitin- 

 ous coat there is a considerable shrinkage of the nucleus (figs. 12, 

 13, 14). Although the substance appears to coiifle directly from 

 the nucleus it is not presumably similar to chromatin in com- 

 position. In the living it is more refringent. When the globules, 

 which arrange themselves at the periphery just inside the spore 

 membrane (fig. 14), are sufliciently numerous they begin to run 

 together. Ultimately a continuous layer one micron in thickness 

 is formed all round the spore (figs. 13 & 15). This is at first 

 colourless, but later becomes light brown but remains translucent. 

 In its behaviour to certain stains this substance also differs from 

 chromatin. Although it stains densely black with iron hfema- 

 toxylin and red with saflfranin, the more selective nuclear stains 

 such as Ehrlich's, Mann's, and Delafield's hfematoxylins do not 

 stain it nearly so intensely as chromatin. In Giemsa preparations 

 the membranous covering of the spoi'e generally stains red and 

 the inner chitinous coat blue, not red like the nucleus. 



The chitinous substance is very resistant : like true chitin, it 

 is not dissolved by boiling in strong caustic potash (30 ^o) '•> ^'^^^^•, 

 on the other hand, it does not acquire the characteristic mauve 

 colour shown by chitin with the iodine in potassium iodide and 

 zine chloride test. Thus it must be concluded that while closely 

 resembling, it is not identical with ordinary chitin. 



(4) Spores. 



The Ti\)e spores vary a good deal in size but are always oval, 

 and when living generally about 10 // long and 6 fi wide. The 

 largest measured was 13 ju long and 8 yu, wide. The latter giant 

 spores seem to be distributed promiscuously ; that is, there is no 

 distinction of cysts into those containing macrospores and micro- 

 spores. Normally the tails into which the outer membrane of 

 the spore is produced are about four times the length of the 

 spore, but they are more or less brittle, and often become broken 

 ofi". The chitinous coat is thick and very resista,nt. It can 

 be softeiaed in various ways, e. g. immersion in Eau de Javelle 

 or weak foi-malin, in order to make it sufficiently permeable 

 for its contents to be stained. Formalin (47,, formaldehyde) is 



