ON PAL^ONTOLOGICAL AND ZOOLOGICAL KESEAllCHES IN MEXICO. 255 



4. To drccTge on tbe const, should time allow. 



I shall proceed to discuss in how fai* each of these jsarts of my pro- 

 gramme has been carried out, but must first explain that almost imme- 

 diately after my arrival in Mexico my health commenced to suffer ; that 

 indisposition soon passed into illness, and that this illness, aggravated 

 by very severe, and as it after svards turned out, mistaken medical 

 treatment, confined me to my room for ujjwards of two months, 

 and left me utterly enfeebled. After my recovery I remained more 

 than a month in hopes of recovering strength and returning to work, 

 and even attempted a few excursions, e.g. to the caves of Caca- 

 huamilpa; but was at length compelled to yield to the urgent advice 

 of my physicians and relatives, and return to Scotland to recruit my 

 health. I therefore sailed from Vera Cruz on 1st March last. It will thus 

 be readily understood that my results, gathered as they are from a period 

 of a few weeks after my arrival (during which my time was largely 

 occupied in the preliminary work of gathering information and improving 

 ray knowledge of the language, not to speak of failing health), are neces- 

 sarily of the most imperfect kind, and that, of various undertakings, well 

 begun, bu^t never finished, nothing can be said at all. I hope, however, to 

 make my memoranda useful to another explorer, my friend M. Joyeux- 

 Laffuie, D.Sc, who proposes shortly to undertake a similar and I trust a 

 more fortunate expedition to Mexico. 



For dredging on the coast there was of course no time. I am con- 

 vinced, however, that excellent results await the fortunate naturalist who 

 can devote a winter to the task, particularly on the Pacific side, which is 

 completely unexplored. 



My collections, though small, were by no means valueless. I obtained 

 a number of plants, mainly from the ravines eroded by streams in the 

 alluvial of the Plateau, and these are of considerable interest, since 

 many are of subtropical fades, belonging to a zone of vegetation consi- 

 derably warmer and lower than the Plateau itself. This tends to throw 

 some light upon the migrations of plants in these countries. The plants 

 growing on the sides of ravines being protected from inclemencies of 

 weather, better exposed to the sun, &c., are thus enabled to reach altitudes 

 otherwise uninhabitable by them. I have presented these dried plants 

 to the Herbarium of the Royal Botanic Garden, Edinburgh, where also 

 some of their seeds are being grown. 



My zoological collection is deposited in the British Museum. It con- 

 sisted of a few mammals, of which two are of considerably rarity, viz. : 

 Spermophilus Mexicanus, Licht., and Blarma micrura, Tomes ; twenty-five 

 reptiles, fifty-two fish, twelve crustaceans, and a few insects. Some of 

 the reptiles, fishes, and crustaceans are of interest to the systematic 

 zoologist, and a note upon some of the crustaceans has just been published 

 by Mr. Miers in the 'Annals and Magazine of Natural History.' I was 

 also able to pro\ade Professor Huxley with a small collection of crayfishes 

 and prawns. 



The microscopical investigation, too, had commenced to yield results of 

 interest. Although in aiitumn the general fades was surprisingly Euro- 

 pean, yet new and strange Protozoa, Rotifers, &c., were by no means rare. 



Despite all hindrances, however, the main inquiry, as to the age and 

 contents of the superficial deposits of the Plateau, came much nearer to a 

 solution. The Plateau is covered to an unknown depth — so great that the 



