M. C. COOKE ON NUCLEATED SPOKIDIA. 



253 



pendent of glycerine than any other, the benzole and glycerine 

 being on good terms with each other. When this luting is dry, 

 which is accomplished in two or three days, the wire clip may be 

 removed. It is advisable now to wash the surface of the slide 

 carefully, by means of a soft camel-hair pencil and water, so that 

 all traces of glycerine may be removed, taking care not to disturb 

 the luting of dammar. When thoroughly dried, after this washing, 

 some tenacious cement should be coated over the dammar, such, for 

 instance, as old gold-size. This adds to the security of the mount- 

 ing. When the cement is hard, in order to provide still more for 

 the permanency of the slide, I cover it with paper in the ordinary 

 manner, and label the object fully. 



By the means now described, I have succeeded in making good 

 slides of sections of Peziza, Truffles, and other fleshy fungi, scarcely 

 distinguishable from fresh sections, and these remain unaltered for 

 many months, except in such cases as I have presently to allude to. 

 Hence I am led to hope that such slides are moderately permanent, 

 whilst, at the same time, more natural than any hitherto mounted 

 by any other plan. The section required for this purpose is so thin, 

 that the quantity of glycerine is very small, and there is so little 

 depth in the mount that an eighth of an inch objective may be em- 

 ployed with advantage. 



Those who have viewed the sporidia of Peziza, especially of such 

 a species as P. lanuginosa, will haye noted that the presence of 

 " nuclei," as they are termed, is so universal in certain species, and 

 apparently so permanent, that they have been introduced into the 

 diagnoses of species. In the case of P. lanuginosa, the sporidia are 

 large, and with two or more nuclei (a a). As far as I have observed 

 this species, the nuclei are present in all stages of growth. Speci- 

 mens were mounted in glycerine last year by the method I have 

 described, and when mounted, all the sporidia had nuclei, some 

 with one or two large, and two or three smaller nuclei, but all were 

 nucleate. Examining the specimen again in a few weeks, I found 

 that all the smaller nuclei had disappeared, and only large nuclei 

 could be seen, whilst some sporidia were without nuclei (b b). 



a 



Sporidia of Peziza lanuginosa, 

 Journ. Q. M. C. No. 17. 



s 



