300 USTILAGINEAE. 



deformans and Peridermium elatinum, as " vegetative canker- 

 galls." On those places are crowded fleshy brittle outgrowths, 

 consisting of an irregular bent club-like stalk, longitudinally 

 furrowed, and expanded at its upper extremity into a broadened 

 head containing the Vstilago spores. Solms calls these out- 

 growths " fruiting galls," -^ and he describes them as follows : 

 " if one of these protuberances be divided, the spore deposit will 

 be found as a flattened violet layer, extending to the margins 

 of the head and roofed in by a slight plate of tissue. This 

 last becomes ruptured, shrivelled, and brown. The violet 

 spores are thus set free, along with a loose woolly capOlitium- 

 tissue, which apparently facilitates distribution of the spores 

 by rendering them difficult to moisten, a contingency very 

 likely to happen in the heavy tropical rains of Java, and with 

 the result that germination would occur before the spores had 

 time to be transported to a new host. After shedding of the 

 spores, the succulent stalk remains. The fruit-galls consist of 

 a hypertrophied tissue developed from the cambium; they first 

 emerge as roundish naked protuberances, covered externally by 

 a smooth epidermis, and containing a meristem from which 

 fibrovascular bundles are developed. The galls are composed 

 of a homogenous parenchyma of large thin-walled cells, elongated 

 in the direction of the long axis of the galls, and containing 

 large cell-nuclei. The epidermis consists of little, polygonal, 

 nucleated cells, and is pierced by a few stomata. The galls 

 are internally permeated by a number of irregularly arranged 

 fibrovascular bundles which show a slightly developed wood 

 and bast region. As the anterior end of the fruit-gall elonsfates, 

 the bundles keep pace by repeated forkings, and form a 

 system of branches diverging at very acute angles and ter- 

 minating a short distance from the surface of the gall. The 

 violet-brown sporogenous layer is situated just at the termination 

 of the bundles, and is covered by a slight layer of parenchyma 

 under the epidermis. The sporogenous layer appears as if 

 composed of columns arranged beside one another in a palisade 

 manner, and connected above and below with the enclosing 

 tissues. At the margins of a section the columns easily separate, 

 and will be seen to consist of a central strand of elongated 

 cylindrical cells filled with a reddish gum-like mass. The cells 



'Friiohtgallen. 



