310 BOTANICAL GAZETTE [OCTOBER 
The morphological individuality of the megasporangium is insisted upon, 
and the same claim is made for the sepal, petal, stamen, and carpel. 
In the chapter upon the female gametophyte the development of this 
structure is followed up to fertilization, including the specialization of various 
parts of the embryo-sac as haustoria, The meaning of the constant occurrence 
of a definite number of chromosomes in each species is discussed, and also the 
criterion for distinguishing megaspore from megaspore mother-cell. 
The chapter on the male gametophyte deals with the formation and ger- 
mination of the microspore, and the reduction question. The authors hold 
that a qualitative reduction of chromosomes is not yet proven. ‘The struc- : 
tures appearing in the pollen grain at germination they believe to represent 
an antheridium only, of which the pollen tube is the much elongated wall- 
cell. 
In the discussion of fertilization, chalazogamy is thought to be an insuffi- 
cient evidence of primitiveness, The centrosome is not demonstrated in 
angiosperms. ‘Double fertilization” is regarded a misleading name for 
the process so called, since this and all other nuclear fusions occurring in the 
embryo-sac probably differ profoundly from the fusion of the male nucleus 
with that of the egg. 
In the chapter on the endosperm the various types of development of the 
part of the embryo-sac dominated by the endosperm nucleus are described. 
The endosperm is believed to be a renewed growth of the female gameto- 
phyte. 
The specialization of parts of the proembryo and embryo for food absorp- 
tion during development is emphasized in the chapter on the embryo. The 
characters of the cotyledons, it is held, cannot yet be considered as prepon- 
derating evidence in phylogeny. The chapter concludes with an account of 
parthenogenesis and polyembryony. 
The reviewer believes that a valuable addition to the book could be made 
by following the chapters on endosperm and embryo with a thoroughly mod- 
ern account of the germination of the seed. 
and suggestive résumé of our knowledge, and ignorance, of the 
iia mataee of the nang CE Archichlamydeae, and Sympetalae 
is contained in chapters x, x1, and x 
eographical distribution and ie angiosperms are treated in the two 
following chapters. There is a concise and very useful summing up here of 
facts concerning these topics, which have been gathered from sources widely 
scattered and often inaccessible, 
The facts of morphology assume definite relation and proportion only 
when they are built into some scheme attempting to express the phylogeny 
of the forms concerned. Such schemes of phylogeny are also the most useful 
indicators, to the investigator, of the forms most likely to yield important 
morphological results. If the scheme followed is erroneous, the worker is 
likely soon to discover the faults of the tool, and the refutation of a wrong 
