1897 } CURRENT LITERATURE 223 
terminally a layer of branches which grow up around it, and presently 
between this layer and the oogonium or carpogonium at least one more 
layer is similarly produced, these layers by further growth and branching 
forming the resultant perithecial wall. The changes which take place in the 
oogonium differ in many respects from those which occur in Spherotheca. 
The fusion nucleus divides repeatedly until there are from five to eight 
nuclei in the carpogonium, which has in the meantime become elongate and 
somewhat bent. Through the formation of transverse septa the latter organ 
then becomes converted into a series of superposed cells, each containing a 
single nucleus, except the penultimate, in which there are always more than 
one. This penultimate cell constitutes the ascogonium, which gives rise from 
all parts of its surface to ascogenic hyphae. The ascogenic hyphz then divide 
to two or three cells, and of these one, which is always intercalary, grows 
directly to form the ascus, five to eight of which eventually mature. The 
cells of the ascogenic hyphz which are destined to form asci are distinguished 
by the fact that they contain two nuclei that ultimately unite to form a fusion 
nucleus which presently divides to form the ascospores. 
The author, in addition to further interesting observations on Erysiphe 
that cannot here be mentioned, also gives an account of the development of 
Ascobolus; which, ‘however, from the fact that no very early stages were 
observed, leaves the question as to the presence or absence of a sexual union 
in this instance still an pie one. The formation of a fusion nucleus in the 
young ascus was det d, and interesting details are presented concerning 
the structure and nuclear characters of the carpogonium. The paper, which 
is clearly written and refreshingly concise, closes with a suggestive discussion 
and comparison of the phenomena above mentioned in connection with some 
of the more recent theories respecting the sexuality of the higher fungi, and 
it need only be noted here that the author is not inclined to admit the sexual 
nature of the nuclear fusions which immediately precede spore formation in 
so many Cases among these plants.—R. T. 
THE INTERRELATIONS of the different sciences is well illustrated in the 
advance that has been made in our knowledge of the action of chemical sub- 
stances on living Peep iace: from the asses Soiseiconnee sarah a 
trend of the paper follows the lines that have recently been developed by 
Kahlenberg and True,” although no reference is made to ust pioneer work 
done by these American investigators who worked upon g. 
As the bacterial spore is not affected by plamolys Pau and Kn nd See 
"7 Zeit. f. phys. Chemie 21: 414. ae 
* Bor. mene 81. 1896. _ 
