74 
Notes on Recent Literature. 
NOTES ON RECENT LITERATURE. 
FUNGI. 
The Cytology of the Uredine,®. 
T HE Rust Fungi have been a favourite group for cytological 
investigation in recent years. V. H. Blackman 1 was the first 
to show that the binucleate condition of forms possessing the 
Caeoma-type of aecidium arises first in the “basal cells” which 
later give rise to chains of ascidiospores. He found that a nucleus 
from the cell below the basal cell migrated into the latter through 
a pore in the wall separating the two cells. He interpreted this 
phenomenon as the fertilisation of a female cell by the migration 
into it of the nucleus of an undifferentiated mycelial cell in default 
of fertilisation by a spermatium, considered by him a functionless 
male cell. Christman 2 later described the binucleate condition of 
other Caeoma-forms as arising by the fusion of two cells 
undifferentiated morphologically one from the other. These fusing 
cells he considered to be undifferentiated gametes, the spermatia 
being interpreted as conidial structures. Blackman however would 
interpret this occurrence as the fusion of female gametes in pairs 
somewhat comparable to the fusion which takes place between the 
female nuclei of the ascogonium of Humana granulata. 
In spite of the divergence in the interpretation of these 
phenomena and the different views held as to the phylogeny of the 
Uredineae by the two authors mentioned, there can be no question 
of the importance of the work done, as they have established quite 
firmly the existence of an alternation of generations in the Rust 
Fungi. 
Christman’s more recent work 3 throws some light on the 
question of the morphology of the different spore forms of the 
Rusts. In seeking the origin of the binucleate phase in species 
which have been described as not possessing an iecidial stage, he 
has obtained evidence that the primary uredospores of the Brachy- 
types are to be identified with ascidiospores. The Brachy-types ot 
Schroeter’s classification are those which possess all spore forms 
except the ascidia. It has long been recognised that the uredo 
pustules of the Brachy-types are of two kinds, viz., those which 
arise first and are confluent and those which arise secondarily and 
are scattered. The mycelium of the former which are called the 
primary uredo pusteles, produces great hypestrophy of the host 
comparable to the distortion caused in other hosts by the presence 
of the aecidial mycelium of other Uredines. It has been noted too 
1 Blackman, V. H. On the fertilisation, alternation of generations 
and general cytology of the Uredinese. Annals of Botany, 
1904. 
2 Christman, A. H. Sexual reproduction in the rusts. Botanical 
Gazette, 1905. 
3 Christman, A. H. The alternation of generations and mor¬ 
phology of the spore forms in the rusts. Bot. Gaz., 1907. 
