148 МЕ. A. BARCLAY ON THE LIFE-HISTORY | 
Montagne, where, as figured by de Bary *, these spores are formed immediately outside 
the peridium by the same mycelium. This suggests the view that primarily teleutospores 
were always formed within peridia, and that in course of evolution they were thrust 
immediately outside (Puccinia Berberidis), then further away (Uredo Behenis, &e.), 
and lastly were produced on separate mycelia, as happens at the present time with the 
great majority of these fungi. 
The assumption of a distributive function in so marked a degree by the tecidiospores 
is, I believe, illustrated for the first time by this species. It renders the production of 
uredospores superfluous, and we have consequently none. 
With regard to the third peculiarity, that, namely, of the germination of the æcidio- 
spores, this naturally suggests affinities with Endophyllum. If the latter may be regarded 
as a starting-point in the evolution of the Uredinz, we have here a connecting-link with 
others. Instead of the гесійіовроге forming a regular promycelium, with sporidia, we 
have, so to speak, an abortive promycelium, stopping short of the production of sporidia, 
but attacking with a sterigmatous branch, the result being alike in both cases, the 
immediate reproduction of a similar spore. In the case of LEndophy lium, however, the 
mycelium is perennial, whilst it is certainly not so in the species under consideration. 
Instead of persisting through an unfavourable time in mycelial form, the latter 
produces, as we have seen, a resting spore, which must be regarded as an advance, 
inasmuch as the production of such a spore must be both more economical and more 
certain for the preservation of the species than a perennial mycelium. Assuming for 
the moment that the Uredineze have started from a form like Endophylium, then it 
is conceivable that an evolutionary course something like the following may have taken 
place :— 
1. First stage scidiospores only, but behaving like teleutospores in producing 
sporidia; preservation of species by perennial mycelium. (Endophylium.) 
2. The same: but with a view to a more economical method of preserving the 
species, the formation of a second kind of spore with resting properties. The 
production of sporidia, which only wastes time as far as a distributive function 
is concerned, is being relegated to the teleutospore. (The species now under 
consideration would be an example.) 
3. A more marked separation of distributive and preservative function in these two 
forms of spores, the latter stil] continuing to assist in distributing, but mainly 
subserving a preservative function (teleutospores which germinate at once after 
maturing, as well as after a rest, е. ©. Æ. Strobilanthis). 
4. А complete separation of these functions, with the production of a third form of 
spore (uredo) to aid in distribution. (Including the majority of species whose 
life-histories are known.) Here, except for special reasons ( mostly unknown), a 
perennial mycelium becomes unnecessary. 
* * Botanische Zeitung,' 1879, no. 48, t. 10. 
