RUSTS. 
321 
the rest have the spores of a decidedly Thrown colour. One 
of the most attractive of the yellow-spored species is that 
which appears on the groundsel [T. Senecionis) , and a good 
notion of its external appearance may be gained from our 
figure (fig. 13). It is not always to be found without searching 
closely, for in some localities I have found it very sparingly, 
whilst elsewhere — as, for instance, on Wandsworth Common — 
I have met with it as soon or as late as there were groundsel 
leaves for it to grow upon. No spot or change in the appear- 
ance of the upper surface of the leaves indicates the presence 
of the parasite beneath ; this is, however, often betrayed by 
the golden-yellow streaks which appear on the stem. Many 
a time and oft the boys in the semi-rural districts about town 
have marvelled and questioned each other concerning the 
reason why, in gathering “ groundsel” for the little bird at 
home, I should be so particular, and pass so many promising 
plants, plucking here and there a leaf, and seldom collecting 
one which they consider eligible for the purpose. Collectors 
of minute fungi must expect to overhear occasionally even 
hints touching their sanity from those who, without the 
remotest idea of their mission, think they must be slightly 
“ wrong in the head ” to gaze so narrowly and intently, 
amongst nettles, groundsel, grass, or dry leaves, and only 
take an occasional fragment of a rotten stick, or two or three 
sickly leaves, carefully deposit them in their wallet, hat, or 
pocket, and then “ move on.” 
It will be unnecessary to repeat what has been stated in a 
former paper on spennogones. It will be remembered that 
these organs are found developed in connection with some of 
the species of the present genus, as well as with the cluster- 
cups, or CEcidiacei . They consist externally of small conical 
elevations, pierced at the apex, which contain minute, cellular, 
linear bodies called spermatia, invested with a kind of mucous 
substance, that overflows with them from the orifice of the 
spermogone, like lava from the crater of a miniature volcano. 
The rust in company with which they have been found most 
plentifully, is that which covers the under surface of the 
leaves of the commonest of all thistles (Gnicus arvensis). The 
external form of one of these spennogones is figured (PI. XII. 
fig. 16). The rust possesses, when fresh, a peculiar odour, 
which is said to resemble that of orange-flowers ; whence was 
derived its name of “ sweet - smelling rust” (Trichobasis 
suaveolens , Lev.). M. Tulasne writes : — “ With respect to this 
species, it is, in my opinion, but the first form of a Puccinia, 
analogous to P. compositarmn, D.C. : the spennogones with 
which it is mixed being very abundant, it ought to be placed 
