450 
AMERICAN JOURNAL OF BOTANY 
[Vol. 8. 
pushed up farther above the epidermis. The tehum here is less compact 
and with less evident lateral coherence of its spore chains. At this point 
in the development of this group, or a little before, a separation into two 
distinct lines apparently takes place. In one line there is an increase in 
the teliospore production from the sporogenous hyphae and a stronger 
lateral coherence of the spore chains; and hair-like columns of teliospores 
are formed, giving us the genus Cronartium. In the other line, there is 
also a greater spore production resulting in longer chains of teliospores, 
but at the same time the lateral coherence of the chains lessens until finally 
in the genus Kuehneola there is a complete separation to the base and a 
falling apart of the spore chains. In consequence of such a development, 
as might be expected, there is no sharp line of separation between the genera 
Cerotelium and Kuehneola and some species are in consequence difficult to 
place, some authors referring them to one genus and some to the other, 
depending upon their interpretation of the limitations of these genera. As 
an example of this transition from one genus to the other, we have the 
following: Cerotelium Gossypii (Lagerh.) Arth. possesses a compact telium 
much like that of C. Canavaliae. In Cerotelium Fici (Cast.) Arth. and in C. 
Vitis (Butl.) Arth., the teliospore columns are much more loosely arranged, 
as has been shown b}^ Butler, but the spore chains still hold together and 
show only a slight tendency to fall apart. In the case of Kuehneola aliena 
Syd. & Butl. and especially in K. Biitleri Syd. we have two rusts which have 
been placed in the genus Cerotelium by Arthur (/. c. footnote 8, p. 510). In 
these species, although the spore chains are short and in consequence do 
not separate as widely as in some species of Kuehneola, the separation is, 
however, definite; and it would appear best to consider both as species of 
Kuehneola. Although DieteP^ (pp. 205-213) was the first to point out 
the catenulate manner of teliospore formation in Kuehneola as distinguishing 
it from the genus Phragmidium, yet he retained the genus in the Puccini- 
aceae, considering it as having developed from Uromyces species on Rubus. 
Kuehneola was, however, removed to the family Melampsoraceae by 
Arthur {L c. footnote 7), largely on account of this catenulate character of 
the teliospore, and these transitional forms support such a disposition of 
the genus. 
The other genera of the Melampsoraceae with teliospores germinating 
without a resting period are Chnoopsora and Melampsoropsis. The former 
maybe considered as arivsing from the same source asAplopsora but diverg- 
ing upon what may possibly be another line of teliospore formation. The 
latter may have arisen from a similar source, most likely from a form 
resembling Melampsora but differing in the development of catenulate 
urediniospores. The method of urediniospore formation in the Aplopsora- 
Butler, E. J. The rusts of wild vines in India. Ann. Mycol. 10: 153-158. 1912. 
Especially pp. 156-158. Also, /. c. footnote 5, pp. 76-79. 
Dietel, P. Uber die Verwandtschaftsbeziehungen der Rostpilzgattungen Kuehneola 
und Phragmidium. Ann. Mycol. 10: 205-213. 1912. 
