series, which brings this, the least of all agaves, close beside the greatest of its congeners, the gigantic Fig. 15. The Lechuguilla. pulque magueys. It would be surprising if, when its flowering is made known, pumila were found to develop a diminutive candelabrum inflorescence; in fact, this is not to be expected. A character shown by this specimen and, so far as I know, never before noted publicly, is that the backs of its leaves are finely lined with dark green on a lighter background. Though generalizations are unsafe, I may say that in the course of an exhaustive study of all of the agaves that it has come my way to see I have thus far seen such lining only on littæas of the horny-margined section, like the lechuguilla—the marking being due, in fact, to the development of what may be called an emergency water tissue on the lower side of the leaves, the darker green stripes marking points at which the full chlorophyll-bearing tissue comes out to the epidermis and the water tissues developing more or less chlorophyll according to differing conditions of drought and exposure to light. There is every reason to believe, therefore, that when it flowers Agave pumila will produce a littæa spike and flowers similar to, if not so large as, those of A. lecheguilla.
No agaves are known south of the isthmus of Panama except one of the West Indian panicled series which has developed in the Venezuelan coast region, and a little-known plant of the Andes, near Lima, which is evidently a littæa, though of a mezcal series, quite unrelated to