37i 
Notices of Books and Papers. 
ceptible difference in the two cases. The cultures of Calicium parie- 
tinum were especially interesting. The spores germinated and grew 
with comparative rapidity, and in five or six weeks black spots ap- 
peared in the thalli, which in less than a week developed into pycnidia 1 
containing conidia, and, from the conidia thus obtained, new cultures 
were made which produced a second crop of conidia, thus giving ‘ for 
the first time incontestable proof of the connection of ascospores and 
conidia in a lichen.’ In Calicium trachelinum , which grows more 
slowly than C. parietinum , there are two conidial forms, one borne on 
arthrosterigmata, the other on simple sterigmata, as first shown by 
Lindsay in Calicium , and both germinate and produce thalli as well as 
the ascospores. 
We hope to hear again concerning the further development of the 
thalli still growing when the present paper was completed, and should 
be glad if the author could furnish illustrations, although, from the 
nature of the material, it must evidently be difficult to provide 
characteristic figures. 
W. G. F. 
TJEBER DIE ABHANGIGKEIT DEB, ASSIMILATION 
GRUNER ZELLEN VON IHRER SATJERSTOFFATH- 
MTJNG, UND DEN ORT WO DER IM ASSIMILATIONS- 
ACTE DER PFLANZENZELLE GEBILDETE SAUER- 
STOFF ENTSTEHT : von N. PRINGSHEIM (Separatab- 
druck aus Sitzungsber. d. k. Preuss. Akademie d. Wiss. zu Berlin, 
xxxviii. 1887). 
Some account of the observations described and discussed in this 
paper was given by Professor Pringsheim at the recent meeting of the 
British Association at Manchester, so that at least the general results 
at which he has arrived are already known to many English botanists. 
But, in view of the importance of the subject, it may not be superfluous 
to give a brief notice of the method employed and of the results 
attained, as well as a discussion of the inferences which Professor 
Pringsheim draws from his facts. 
The object of the investigation was to determine (1) what relation, 
1 The author, regarding the spermatia as conidia, uses the term pycnidia to 
include spermogonia as well as the pycnidia proper which are found in some 
species of lichens. 
