52 LINUSAV, ON ABROTHALLUS. 



" lode protoplasma fucatur, membraiia autem utriculi vix mu- 

 tatur/' I did not find iodine produce any change further 

 than communicating its own tinge. Like the spermatia, 

 the stylospores are borne on a series of sterigmata^ closely 

 crowded together^ and arranged in relation to the w alls and 

 cavity of the pycnidis as the sperniatial sterigniata are to 

 those of the spermogone. Bvit the filaments generating the 

 stylospores are uniformly simple and one-spored — the stylo- 

 spore invariably being thrown off from the apex, and never 

 from the sides. These filaments vary greatly in length; 

 generally they are very short or inconspicuous ; sometimes 

 they appear to be absent. There is considerable variety also 

 in thickness; being sometimes thick and short, at other 

 times long, slender, and thin. In both cases they are 

 usually very delicate. Sometimes they become shrivelled, 

 and are retained, as caudate appendages, by the stjdospores ; 

 this I frequently observed in the small yellow stylospores in 

 Highland specimens. Each sterigma w^ould aj)pear to gene- 

 rate — as do also the spermatial sterigniata — a continuous 

 series of stylospores, which in this case are thrown off as termi- 

 nal cells or buds. The sterigmata of A. Smithii, Tulasne de- 

 scribes as " bre\dssimis stipatissis quandoque \ix conspicuis 

 crassis ac monosporis ;" while, in A. microspermus, they are in- 

 conspicuous and but rarely " linearibus et longiusculis." The 

 stylospore first appears as the rounded, bulging, or obovate 

 extremity of a short, simple filament, which resembles, 

 except in length, the paraphysis of a lichen. The end of 

 this filament is full of a finely granular matter, Avhich accu- 

 mulates especially in the bulging portion ; the latter is 

 gradually separated by a septum. The terminal cell becomes 

 broader towards its free end, and narroAver towards its inser- 

 tion upon the sterigma, until, at length, it is thrown off as 

 the stylospore. The latter appears to attain its full size 

 only after it is free ; it expands in all its dimensions and 

 acquires a pyriform shape. The granular protoplasm now 

 becomes more distinct and more coarse ; there is a gradual 

 fusion of the smaller granides into globules, and these into 

 larger globules, until the cavity of the stylospore is occupied 

 by one or more large globules as 1 have already described. 

 Knally these appear to deliquesce into a homogeneous, 

 colourless, oily fluid, which gives rise to the colourless pyri- 

 form stylospore with apparent double contour. 1 have seen 

 nothing like germination in the stylospores. 



Stylos2:)ores have been hitherto found only in another minute 

 parasitic genus— also described recently by Tulasne in his ad- 

 mirable memoir on the organography and physiology of the 



