636 



SCIENCE. 



LN. S. Vol. VIII. No. 201. 



so far from ripening several crops annually, is 

 killed down every winter, except in sheltered 

 places, as between four walls, and does not pro- 

 duce any crop unless thus protected. In short, 

 the products of the Eio Grande and Pecos val- 

 leys in New Mexico are Upper Sonoran, not 

 Lower Sonorau at all, although it is true that 

 there are some elements in the fauna and flora 

 ■which may even be called neotropical. 



These facts are not new, nor is this criticism 

 of Dr. Merriam's map here made for the first 

 time. In the plainest possible language, I drew 

 attention to the real status of the case in Bull. 

 15, of the N. M. Experiment Station, January, 

 1895, pp. 54, 55. Again I protested against Dr. 

 Merriam's mapping in Bull. 17 of the same sta- 

 tion, April, 1896, p. 100. Still again the sub- 

 ject was discussed in Bull. 24 of the same station, 

 August, 1897, p. 7, etc. In the publication last 

 cited are quotations from an excellent letter by 

 Dr. T. S. Palmer, of the Biological Survey, ad- 

 mitting that the products assigned to the Lower 

 Sonoran do not grow all over that area as 

 mapped ; but in the work now criticised there 

 is no hint of this. 



Professor C. H. T. Townsend, who has long 

 studied the distribution of life in New Mexico, 

 has also expressed himself clearly and explicitly 

 on the point at issue. He further explains the 

 limits of the Lower Sonoran in Arizona, Mexico 

 and Texas, on pp. 84, 85 of his paper in the 

 Proceedings of the Texas Academy of Science, 

 vol. 1. In a second paper in the same Proceed- 

 ings he has further discussed the fauna and 

 flora of Mexico and the southwestern United 

 States, giving many new facts and arguments. 



Neither Professor Townsend nor the present 

 writer imagine that we are withiu a measurable 

 distance of reaching iinal conclusions on zone- 

 distribution in the West; but the facts mentioned 

 above, ignored by Dr. Merriam, are matters of 

 common knowledge to every inhabitant of this 

 region. Certain persons interested in the sale 

 of lands have from time to time circulated false 

 statements as to the products of southern New 

 Mexico, which statements have been duly cor- 

 rected. But now, for their most extravagant 

 assertions, they can fall back on the authority 

 of the Chief of the Biological Survey ! 



We all owe thanks to Dr. Merriam for the 



large amount of extremely valuable work he 

 has accomplished during the last ten years, but 

 this fact cannot protect him from criticism when 

 he deliberately reissues misleading statements 

 and maps, totally ignoring the protests of those 

 who are working in the region discussed. He 

 not only perpetuates a scientific error, but runs 

 the risk of seriously misleading those farmers 

 whom he invites to guide their operations by his 

 aid. 



t. d. a. cockeeell. 

 Mesilla Park, N. M., 

 September 23, 1898. 



Me. Cockeeell finds fault with me for in- 

 cluding certain parts of the valleys of the Rio 

 Grande and Pecos in the Lower Sonorau Zone, 

 and makes the positive statement that they are 

 in the Upper Sonoran Zone. At the same time 

 he admits that the faunas and floras of these 

 valleys are mixtures of at least two zones. In 

 this I quite agree with him. He considers the 

 preponderance of species Upper Sonoran ; I 

 considered it Lower Sonoran. The difference 

 between us, therefore, relates to the position of 

 the boundary line — a line separating adjoining 

 belts in a narrow valley. He thinks I have 

 carried it too far north. He may be right. 

 But he omits to quote from my Bulletin an im- 

 portant statement intended to cover this class 

 of cases. In discussing the northern arms of the 

 Carolinian faunal area I said: "These arms, 

 like nearly all narrow northward prolongations 

 of southern zones, do not carry the complete 

 faunas and floras of the areas to which they 

 belong, but lack certain species from the start 

 and become more and more dilute to the north- 

 ward till it is hard to say where they really end. 

 Their northern boundaries must be drawn arbi- 

 trarily, or must be based on the presence or 

 absence of particular species rather than the ' 

 usual association of species." 



This seems to dispose of the main point of 

 Mr. Cockerell's criticism. The absurd claim 

 that all the crops mentioned as growing in a 

 particular zone will grow in all parts of that 

 zone has never been made by me. And as to 

 the map, it seems hardly necessary to say that 

 one on so small a scale as that accompanying 

 the paper in question can hardly be expected to 



