20 MR. G. BENTHAM ON GRAMINE. 
instances I cannot approve of his distinctions or combinations of 
genera or species. That may, however, be a matter of opinion 
only; but in regard to several of the exceptional characters he 
gives, such as the five lodicules of Pariana or the three of Aris- 
tida, they have not been verified on reexamination ; in his spe- 
cific names he has not unfrequently departed from the established 
rules of nomenclature without giving any special reasons for so 
doing; and there is a general carelessness in redaction showing, 
for instance, on several occasions that when he had found reason 
to modify his first ideas as to the limits of species, he had neglected 
to revise his manuscript accordingly. He also makes frequent 
use of the expression “partis nomine," the meaning of which 
neither Munro nor myself, nor any of our classical friends to whom 
we have applied, can make out. Eugène Fournier’s ‘ Enumeration 
of Mexican Gramine& ? is not yet published; but being already 
printed off, and M. Fournier having obligingly supplied me with 
a copy, I feel bound, in so far as I am concerned, to treat it as 
having already taken date.’ He has had at his disposal rich col- 
lections of the grasses of a country where they are perhaps more 
local and varied even than in South Africa; and he has made good 
use of these materials, although there is still much to be learnt 
with regard to Mexican forms. We have at Kew several, not 
only species but genera, which are not included in his work ; and 
there are not a few of his which I cannot recognize in our gene- 
rally rich Kew collections. A further comparison is also required 
with extra-Mexican genera and species, and especially with those 
of extratropical South America. His genus Zesourdia, for in- 
stance, had already been published for a southern species by 
Philippi under the name of Seleropogon. His Trichloris is re- 
presented in the south by two species separately recognized by 
Munro and by Jean Gay as constituting a distinct genus, but 
under names hitherto unpublished, which must therefore give way 
to Fournier’s. Ina systematic point of view also his work would 
have been much more useful if he had more frequently given the 
characters of the tribes, genera, or other groups which he has 
modified, instead of limiting himself to dichotomous keys. These 
dichotomous keys, when carefully drawn up, are of the greatest 
use as guides or indexes to direct the botanist where to look for 
his plant, but are wholly insufficient for its identification either 
generic or specific. For above sixty years I have had great 
experience both in using and in making them. It was with the 
