KICVll'.WS 1T'.> 



convincing way arc the unusual early growth of pine on old Ik-Ids and 

 the effect in different conditions of fire. 



It was intimated earlier that in one respect this work might perhaps 

 not adequately meet the requirements of those at whose needs it is 

 directed. Reference was made to the presentation. A day or two of 

 clear time for reading and digestion, it might seem, should not be 

 begrudged a thorough-going book by those whose interest or interests 

 it touches, yet few probably, whether business men or of the profession, 

 make up their minds to it. Though in logical order and not over- 

 technical, the work is not easy reading, while the great number of 

 tables contained make it really formidable looking. In every one of 

 these to be sure there is meat and meaning, but present results from 

 the bulletin might perhaps have been greater if it had been put up in 

 two sections, text and an appendix. 



However that may be, the work is a monumental one. Seeing that 

 it is now six years since it came out and that his labors meanwhile 

 have been applied in other fields, it is probably true that Mr. Ashe has 

 forgotten more about loblolly pine in and bordering North Carolina 

 than any but a very few living men will soon know about it. 



Austin Carv. 



The Adventitious Nature of the So-Called Medidlary Rays. By 

 Herbert Stone. Cambridge, England, September 10, 1920. Printed by 

 Butler and Tanner, Frome and London. Pp. 11, pis. (1, list of 20 

 references, none later than 101-1. 



The author expresses the opinion that the rays are "stop-gap-tissue." 

 He concludes that "whenever a gap, however caused, occurs in the 

 wood in the neighborhood of living cells, the space is filled by new 

 tissue produced by those cells." (Trecul's idea, 1852, with reference 

 to the potentiality of young living cells, not cambium.) "This new 

 tissue is called, according to circumstances, rays, callus, flecks, or 

 tyloses. The ray is the tissue occupying a slit rent in the cambium by 

 the increase in the periphery of the stem, chiefly at the period when 

 the cambium is dormant. The slit is a wound that is kept continually 

 open by the same increase in the periphery. As the cambium has 

 double duty to perform at those points it lags . . . and notches or 

 indentations on the transverse section are produced in the contour of 

 the rings. The form of the ray and the prostrate position of its cells 

 are due to the occupation of a horizontal slit. The ray tissue in its 



