io6 
Review 
“ the only Xanthocapsa associate that is silicicolous ” and on the opposite 
page Psorotichia lugubris is listed. The statement on p. 250 that rust 
lichens “grow on rocks that are frequently under water'’ needs qualify¬ 
ing, as only one of the four examples given grows in such situations, and 
other exceptions could be mentioned. The formula of such a highly com¬ 
plex substance as triethylprotocetraric acid may still be given as 
C 20 H 18 O d , even though it is an empirical one (p. 221). The “yellow- 
coloured medulla of Parmelia subaurifera” (p. 226) is usually white in 
southern plants. In the resume of the work done on the shingle lichens 
at Blakeney Point, Lecanora badia is given as abundant. During some 
observations on the shingle beds in 1921, L. badia was not seen, though 
Lecania prosechoides was abundant and is probably the lichen meant. 
Placodium lobulatum was also abundant on the low shingle and is prob¬ 
ably the lichen referred to as Lecanora citrina var. incrustans. 
Some biologists may reasonably object to the use of copulation for 
contact or fertilisation (p. 160, etc.), rhizoid for rhizina (pp. 92 and 93) 
and prothallus for hypothallus or protothallus (p. 187), as their use may 
cause confusion, or are scarcely in accordance with their use in other 
branches of biology. The physiological meaning of the statement quoted 
on p. 224, about waste products and products of deassimilation is rather 
obscure. Bitter’s suggestion of hybridity between Parmelia physodes 
and P. tribulosa, owing to the intermingling of their soredia (p. 146), 
would be more convincing if the specific segregation of these two plants 
was established. The phylogeny of the Coniocarpineae (p. 276) may be 
more easily explained by assuming that their fungal ancestors belong 
to an extinct group. 
The general get-up of the book is excellent; headings, spacing, wide 
margins and illustrations give an artistic setting which such a great 
work deserves, but (and there is a very objectionable but) the price is 
much too high. The work ought to be readily accessible to every student 
of plant-life, and the high price will prevent such a desirable consum¬ 
mation. Perhaps it would have been advisable to place some of the 
more critical matter in smaller type, if such a course would have re¬ 
sulted in a cheaper book. Much of the matter dealing with the chemical 
contents of the cell could have been so treated. 
A general consideration of the book makes one realise what a great 
diversity of opinion exists on very many lichenological questions. Even 
in regard to the distribution of lichens in the Polar regions, Darbishire 
and Hue are at variance. According to the former 50 per cent, of Ant¬ 
arctic lichens are also Arctic, whilst Hue states that 81 per cent, of 
Antarctic lichens are special to this southern region. The magnitude of 
the task in considering and coordinating such a variety of views so as 
to form a connected story may well have appalled a stout heart, and we 
may be proud of the fact that it has been so splendidly accomplished by 
one of our own botanists. 
W. WATSON. 
