NOTES AND QUERIES ON RUSSULA5. 
35 
for the brown forms, each characterized by very much crowded and 
very narrow white gills. 
We presume that there always will he, with the most carefully 
arranged classification of species, instances occurring in the ex- 
perience of all, of isolated individuals which it is difficult to place. 
It is a common occurrence, perhaps, with the most experienced, 
but even in such cases, wherever careful drawings have been kept, 
time may provide the missing link. As a rule, it is doubtful 
whether these isolated individuals are worth the labour they 
entail, because they are mostly isolated, and the result of some 
accidental variation. Whereas it is with constantly recurring, and 
reasonably permanent, types that our best time will be spent. 
The only other species to which we shall now allude is R. 
xerampelina , not at all a common one, and perhaps sometimes 
carelessly referred to R. integra. As to the colour of the pileus, 
all the variability seems to be in the intensity of the marginal 
colour, the disc holds its character of tawny yellow, verging on 
reddish brown, broken up into little punctiform scales. The 
marginal tint is purple, with more or less admixture of red or 
brown, but differing, as in other species, more in the intensity of 
the colour than in any variation in the elemental colours. There 
need be no hesitation with such a well defined species, when suffi- 
ciently mature to see the characteristic features of the disc, com- 
bined with the form and tint of the gills. 
Of the coloration of the stem little can be said of any of the 
species in which it occurs. It is rarely constant, especially where 
the colour is red ; species, such as R. Queletii, in which it is purple, 
are more invariable, and those in which the stem becomes grey, R. 
depallens , R. ochroleuca, etc., the stem is at first white, and the 
grey colour is acquired by age, and is always faint, but indis- 
putable. 
Before leaving the stem, it may be pertinent to observe that in 
the diagnosis of some species considerable emphasis is placed on 
the rugosity of the stem. It is not infrequent to read that the 
stem is reticulately rugose. Admitted that it is more strongly 
marked in some species than in others, yet it appears to us that if 
a lens is employed, as it often is by an enthusiastic mycologist, he 
will probably grow sceptical as to whether there is such a thing as a 
species of Russula with a perfectly even stem, free from striae in all 
ages and conditions. If so they are, at least, more rare than abso- 
lutely rugose stems. 
Internal changes of colour, or discoloration of the flesh, seems 
to be a valuable character, where it assumes a positive and definite 
tone, and does not bear the impress of caprice, as often appears to be 
the case in externally coloured stems. Russula nigricans, R. densi- 
folia, R. semicrema, R. decolorans, R. rhytipes, and some others seem 
to depend almost for their strongest features on the colour or dis- 
coloration of the flesh. This is the most redeeming feature in 
R. Du Portii. It seems to be characteristic of R. Barlce, and also 
