28 i 
E. J. Salisbury. 
DESCRIPTION OF PLATE VI, 
Illustrating Mr. Price’s Paper “On POLYPORUS 
SQUAMOSUS Huds.” 
Fig. 1. Four cultures showing fructifications which are chiefly of the 
branched type. 
Fig. 2. A larger view of a similar type, showing the characters of the 
mycelium and the exudation of liquid drops towards the base. 
Fig. 3. Mycelium on the wood of Finns. Note the very sparse growth 
here obtained. 
Note Added September 25th, 1913. 
Since the above was in the press, one of the cultures in bright light has 
produced an interesting fructification. This culture was further nourished by 
pouring into the tube some of the peptone containing solution already 
mentioned. The fructification is long and stalk-like, but is slightly spathulate 
and flattened at one end, while on one surface is present a system of irregular 
pores, much resembling those which occur at the base of the normal Polyporus 
fructification. There is thus reason to hope that this fructification will be 
found to have produced a hymenium, and possibly basidiospores, but it has 
not yet been examined for this. 
Thus, as was surmised above, bright light cannot have any direct 
inhibitory effect on the development of the fructifications. 
THE DETERMINING FACTORS IN PETIOLAR 
STRUCTURE. 
By E. J. Salisbury, B.Sc., 
East London College , University of London. 
T HE organisation of the petiole is intimately related to that of 
the leaf which it bears and we should expect, on d priori 
grounds, that variations in the structure of the one would be 
reflected in those of the other. One of the most important 
questions that arise in this connection is how far differences in the 
potentialities for transpiration between leaves of the same species, 
or those of different species, affect their respective vascular 
organisations. 
