57 



In Journ. Washington Acad. Sciences, VI: 109 (1916) I de- 

 scribed what purported to be a lower Cretaceous Flora in Color- 

 ado. The only species I definitely identified was Matomdiiim 

 althausii, a well-known Lower Cretaceous fern. Some additional 

 evidence came to light, and in view of the apparent complications 

 it was thought well to refer the material to Dr. Berry, who pub- 

 lished a very valuable article in Bull. Torrey Bot. Club, 46: 285. 

 Berry concludes that the Matomdiiim is a distinct species, 

 which he names M. americanum. With this decision I have no 

 quarrel, but I call attention to the subject to illustrate an unfor- 

 tunate tendency in paleontology to convert suggestions into 

 positive statements in quotations. Berry states that my plants 

 came from "the supposed McElmo," but I said the deposit was 

 "above the McElmo." A fossil which Berry (no doubt cor- 

 rectly) considers to represent the apical part of a Matonidium 

 stipe, I said closely resembled Cycadospadix. Berry says twice 

 that I "referred" it to Cycadospadix. Knowlton, in his list on 

 p., 732, cites from my paper without any query Egiiisetum 

 burchardti and Sapindopsis variabilis, but in the main list a query 

 is given with the latter. I said, "stems . . . may well represent 

 the species Equisetum burchardti, but the sheaths are unfortun- 

 ately wanting," and "leaves . . . may well belong to" Sapin- 

 dopsis variabilis, "although the lateral veins appear to form a 

 more acute angle with the midrib than in that species as figured 

 by Berry." Berry thinks both suggested identifications are 

 wrong, so my cautious language was justified. In nearly all 

 paleobotanical work there is necessarily a considerable margin 

 of error, so that when hesitation or doubt "appears it should 

 never be converted without investigation into apparent certainty. 



T. D. A. COCKERELL 

 Brown's "Forest Products"* 



Botany is the foundation of all sciences dealing with plants. 

 Agriculture and forestry are but applied botany. Brown's 

 "Forest Products" will interest botanists and all those who like 



* Brown, Nelson C, "Forest Products, Their Manufacture and Use," xix + 471 

 pages, frontispiece and 120 figures. John Wiley and Sons, New York, 1919. 

 Net ?3.75. 



