104 
The object of the book, the author says, u is to obtain an insight into 
the life history and structure of the species of parasitic cryptogams oc¬ 
curring in Great Britain.” 
In the chapter on spermogonia considerable attention is paid to the 
attractions offered to insects by the saccharine qualities and odor of 
the spermogonia themselves and the bright color of the spots on which 
they are produced. A large number of experiments on the germination 
of spermatia were made, and the author succeeded in germinating the 
spermatia of the rncidia on Beilis perennis , Ranunculus bulbosus, R. 
ficaria , Anemone coronaria , Lapsana communis , and some others, but he 
did not succeed in infecting healthy plants. He discovered important 
differences between the budding spermatia and true yeast spores, in 
that the former did not produce alcohol. The function of the sper¬ 
matia is discussed at some length, and the author concludes that the 
balance of evidence points to the conclusion that the spermatia are not 
sexual organs, but may possibly be conidia. 
An important item in the chapter on secidiospores is the fact that 
Plowright could not induce them to germinate after forty-eight hours, 
contrary to DeBary, who states that they retain their germinative fac¬ 
ulty for some weeks. * 
Under Uredospores he notes the production of sporidia when the 
germ tube can not enter a stoma, and discusses the significance of para- 
physes occurring with the uredospores. He considers them as morpho¬ 
logically analogous to the pseudo peridial cells of the aecidiospores, and 
says that wheu uredospores do not arise directly from the mcidiospores 
they are constantly present, but hardly present at all when the uredo¬ 
spores arise directly from the secidiospores. He thinks that this indi¬ 
cates that they are an indication of exhaustion of vital energy, which is 
combated by protective efforts on the part of the fungus in preserving 
the spores it does produce. 
Considerable space is devoted to the influence of barberry bushes on 
wheat and to the development of the knowledge of the lieteroecism of 
the Uredinece. The latest results on the subject are given in a tabular 
statement which may be summed up as follows: Forty-seven teleuto- 
spore forms have been connected with their corresponding secidia. Of 
these Plowright himself has established the connection in eleven cases 
and verified it in twenty-seven others. 
The Ustilaginew are dealt with in essentially the same manner as the 
Uredinece. After a short chapter on the mycelium, the author devotes 
a much longer one to spore formation, which he describes in detail for 
each genus. The chapter on germination includes descriptions of germi¬ 
nation in all the different genera, together with fifteen species of Usti- 
lago , five of Urocystis and three of Entyloma. 
The chapter on Infection of Host Plants by the Ustilaginew is devoted 
to discussing as to when and where the germ tubes of Tilletia tritici and 
Ustilago segetum enter the young plant; while this has been practically 
