52 
NOMAD fUNGI. 
tussilagiiiis; yet the Pucciuia has been hitherto unknown in Britain, 
while the CEcidinm occurs in vast abundance everywhere. A similar, 
but reversed, instance occurred in another of his experiments, where 
he produced (Ecidiiini zonule (a plant new to the British flora) by 
sowing the spores of Uroinijces junci. Even if we grant that the newly- 
discovered fungi did exist before in Britain, it must be in small 
quantity and in few places only. So Peridermium pint is a stage of 
Coleosporium senecionis ; the latter is very common miles away from any 
locality where the former can be found. Stages II. and III., or their 
physiological equivalents, must indeed occur in most cases ; but the 
oecidium-stage need perhaps only occasionally intervene. Vide infra. 
In the genus Phragmidium the oecidium-stage has been hitherto 
but little known (I might say, in England altogether unknown),* and 
frequently confounded with the uredo-stage. In both cases the sori 
are surrounded by a ring of paraphyses, but in the case of the oecidium- 
sorus the spores are produced in chains ; in the uredo-sorus each spore 
grows singly. For Triphragmiurn no stage I. has yet been discovered,! 
which is also the case with our species of Melampsora. In Melampsora 
and Coleosporium, stage II. is the ordinary uredo-like form, in which 
the spores occur in heaps like dust; stage III. is that in which the spores 
are closely compacted; in Melampsora, 1 to 4-celled and with a 
thickened cuticle ; in Coleosporium, mostly 4-celled and surrounded by 
a tenacious gelatine. Gymnosporangium (with which Podisoma is 
united) has for stage I. the various species of Kcnstelia. Of Cronar- 
tium, which has been discovered in Britain since the publication of the 
Handbook,! only stages II. and III. are known. Peridermium is stated 
to be the first stage of Coleosporium, but concerning this it is, I think, 
permissible to withhold one’s opinion till further evidence is adduced. 
Endophyllum is a curious genus, in which the spores are produced in 
chains, and surrounded by a pseudo-peridium, exactly as in CEcidium, 
but nevertheless germinate like those of a Puccinia, with the forma¬ 
tion of a proniycelium and small round sporidia. It is found 
embedded in the leaves of Euphorbia ainygdaloides and species of 
Sempervivum and Sedum. Dr. B. White has described (in “ Scottish 
Nat.,” iv., p. 168) a new genus, Milesia, allied to Endophyllum, found 
in the leaves of Polypodiurn vulgare. 
Of the genera included in the Handbook, which are not mentioned 
in the foregoing list (p. 28), Xenodochus is absorbed in Phragmidium 
(a change hardly to be recommended); Tilletia, Ustilago, Urocystis, 
Thecaphora, and Tuburcinia are placed in the Ustilaginese; Cystopus 
is removed to the Peronosporeae ; Trichobasis is merely a synonym of 
Uredo ; and Graphiola is not truly British. A number of species. 
* Mr. Plowright has recently recorded it in “Science Gossip” for January, 
1883, pp. 11-12. 
+ The uredo-stage has, however, two forms—the one appearing in spring, 
physiologically, perhaps, but not morphologically representing the CEcidium 
the other in summer being the true Uredo. 
I See “ Grevillea,” iii., p. 124. 
