162 BOTANICAL GAZETTE [AUGUST 
the stems is slight, but in the leaves the cells undergo more active divisions 
than those of normal leaves, and the intercellular system is more developed. 
These changes seem to be characteristic of the fungus, but most of the other 
morphological changes associated with it can also be induced by other con- 
ditions. Both in the stem and in the leaves the localization of the mycelium 
is dependent upon the presence of soluble carbohydrates in the tissues. 
In the later stages of development of the plant, processes of disorganiza- 
tion begin. The death of the leaf cells is accompanied by processes character- 
istic of cells which are being slowly poisoned. Of the parts of the fungus the 
haustoria are the most persistent. In the rhizomes they become greatly 
developed and form a sort of pseudo-parenchymatous tissue in the cells, but 
they are not the sources of infection in the following year. 
Of interest in connection with a consideration of the relations between 
parasitic fungi and their hosts are the experiments of MORGENTHALER‘ show- . 
ing that the production of teleutospores is determined more by the state or 
condition of the host than by the influence of external factors. The author 
investigated the factors inf ing the production of teleutospores of Uromyyces 
Veratri on Veratrum album. He found that cutting the veins of leaves or 
wounding the leaves in other ways led to a production of teleutospores in the 
neighborhood of the wounded tissue, while in the other areas of the leaf uredo- 
spo:es predominated. In general, any cause that affects the leaf unfavorably 
leads to the production of teleutospores. In standing plants teleutospores 
are first formed on the lower leaves because these lose their vitality first; but 
if the plants are cut and kept in water, the upper leaves wilt and become dis- 
colored first. In that case teleutospores appear on the upper leaves first, even 
if all have been inoculated at the same time. From a number of such experi- 
ments the author concludes that the production of teleutospores is determined 
by the changes leading to the withering or dying of the infected parts of the 
host plants. This conclusion is further strengthened by a number of observa- 
tions on the distribution of uredospores and teleutospores in relation to the 
state of the infected parts of the host in herbarium material. 
KUusANoS gives an account of chloranthic deformation of the flowers of 
Prunus Mume caused by the mycelium of Caeoma Makinoi. As a result of 
the action of the mycelium of this fungus on the primordia of the floral parts, 
the course of their development is changed so that leaflike structures are 
produced in place of floral organs. The degree of transformation differs in 
different flowers. In extreme cases the cuplike receptacle bears a tuft of well 
developed leaves which in no way resemble floral organs. In other cases leaves 
take the place of only one or more of the whorls of floral organs, or some of the 


* Morcentuater, O., Uber die Bedingungen der Teleutosporenbildung bei den 
Uredineen. Centralbl. Bakt. IT. 27:73-92. figs. 18. 1910. 
5 Kusano, S., On the chloranthy of Prunus Mume caused by Cacoma M. akinoi. 
Jour. Coll. Agric. 2: 287-326. pls. 17, 78. Igtt. 

