20 ME. G. BENTHAM ON GEAMIKEJE. 



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 oiAris- 

 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. Eugene Fournier's ' Enumeration 

 of Mexican Graminese ' 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 

 iise of these materials, although there is still much to be learnt 

 with regard to Mexican forms. "We have at Eew 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 extrabropical South America. His genus Lesourdia, for in- 

 stance, had already been published for a southern species by 

 Philippi under the name of Soleropogon. 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 under names hitherto unpublished, which must therefore give way 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. In a 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 insufiicient 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 



