IIo Transactions British Mycological Society. 
would perhaps have made the book of undue length if some of 
these fascinating phases of the biology of the fungi had been 
explored in greater detail. 
The author is a well-known worker on the cytology of the 
fungi, and her supreme interest in this aspect of mycology is 
evident throughout the book. She is an ardent believer in the 
existence of two nuclear fusions and two reduction processes in 
the life-cycle of the Ascomycetes, and is the founder of the term 
“brachymeiosis” to denote the third nuclear division in the 
ascus as described by her and others. Mention is made of the 
alternative view, that, like all other organisms of a sexual nature, 
the Ascomycetes possess only a single nuclear fusion and re- 
duction process in their ontogeny. The author sums up this 
divergence of outlook as follows: “according to our present 
knowledge of the cytology of the Ascomycetes there are two 
nuclear fusions in the life-history of these plants,”’ a statement 
which, in view of the large amount of recent work that points 
in the other direction, is somewhat surprising. However, as an 
account of the comparative morphology of the sexual organs 
of the Ascomycetes there is no book to approach it in excellence. 
The chief innovation in the classification of the Ascomycetes 
is the institution of the group, Plectomycetes, to include the 
Plectascales (Endomycetaceae, Aspergillaceae, etc.), Erysi- 
phales, and Exoascales. This is a very convenient arrangement, 
but its significance is uncertain, for, as the author emphasises, 
further investigation is required before much is known about 
the phylogenetic inter-relationships of the Ascomycetes. It is 
undoubtedly right to remove the Erysiphales from the Pyreno- 
mycetes. In the general treatment of the Ascomycetes there 
are some notable omissions: for instance, there is no mention 
of such a common fungus as that causing apple canker. 
Short chapters are devoted to the Ustilaginales and the 
Uredinales, but, apart from details of cytological development, 
the information is rather fragmentary. The occurrence of in- 
fection through the flowers in certain smut fungi of cereals is 
not mentioned, and there is only the barest reference to Hemileia, 
the most important rust genus in the tropics. 
The letterpress and illustrations of the book are excellent. 
The wealth of figures is. amazing, and they are beautifully 
executed, largely by the author herself. It is a special pleasure 
to see a reproduction of Cyttaria Gunnii from Berkeley. Un- 
fortunately the price of the book is high (35s.), but it is indis- 
pensable to all serious students of fungi. 
Bet. (Bs 
