130 BOTANICAL GAZETTE [FEBRUARY 
the uppermost terminus, and its glumes are situated so as to alter- 
nate with the four leaves (Z'-L4) borne on the culm. - 
Such is the usual composition of the fasciculate shoots in Munroa 
squarrosa, but there are of course many variations in proportion to 
the number of shoots developed. However, the succession of leaves 
appears constant, and the modification by suppression of some of the 
spikelets or of the vegetative shoots does not influence the principal 
structure as described above. It is a structure which no doubt is 
uncommon among the Gramineae, even if the components of the 
shoots may be identical. Somewhat similar and equally complicated 
cases of ramification may be observed in Coix, in Andropogon, and 
especially in Jouvea. North American Gramineae exhibit altogether 
a number of types in regard to inflorescence and ramification of axes 
which are very little known and which deserve attention. In Munroa 
the most striking peculiarity depends, as stated above, upon the 
presence of short internodes with green leaves above the longest 
internode of the culm, preceding the terminal inflorescence. Fur- 
thermore, it is characterized by the profuse development of shoots, 
floral and vegetative, from the axils of these leaves; and also by the 
elongation of some of these into secondary culms, at the apex of 
which the same development of fasciculate shoots occurs. 
From a morphological aspect, therefore, Munroa squarrosa oflers 
several important characters, but it exhibits also some points of 
histological interest, which may be mentioned in this connection. 
As an inhabitant of the arid plains, it would be expected that our 
plant would possess a xerophytic structure, which it does; but such 
structure is far from common among its associates. Ecological 
studies are very seldom extended beyond the mere fact that such and 
such plants constitute associations; whether the external and internal 
structure of such xerophytes, for instance, is in real harmony with 
the surroundings is very seldom touched upon. The xerophytic 
characters have been very excellently defined by several prominent 
authors, by WARMING and ScHimpER for instance; but whether 
these characters are to be observed in all the members of such 
xerophilous associations remains to be seen. It would require a? 
immense amount of work, and nothing more or less than a complete 
investigation of the internal structure of desert plants. Very few 
