22 The Ohio Journal of Science [Vol. XX, No. 1, 



The writer is not familiar with any literature dealing with 

 the localization of branch forming elements in the conifers, 

 although their highly symmetrical habit of branching had 

 often impressed him. While this proliferation was thickest 

 in the younger part of the stem where material might be con- 

 sidered more condensed, the fact that it was found also on the 

 older portions of the stem seemed to indicate that these branch 

 forming elements are by no means limited in locality. They 

 appear to exist everywhere on the stem, and apparently need 

 only the proper stimulus to cause them to grow out. Moreover 

 the full history of the secondary branches shows that where 

 each primary branch emerges from the trunk it is apparently 

 surrounded by the branch forming elements of the secondary 

 branches — the primary branch then becoming comparable 

 to the hub of the wheel. The writer's observation has been 

 that these secondary branch elements rarely develop under 

 normal conditions into branches at this basal position, but 

 undoubtedly portions of them are carried along in the lateral 

 growth of the primary branches, and under appropriate con- 

 ditions develop the secondary ones. 



The hardy character of the trunk and such a distribution of 

 branch forming material under the circumstances described, 

 may be granted a distinct advantage. While many of the older 

 branches were destroyed, yet the younger proliferating elements 

 were rapidly filling their place, at their base, as well as between 

 nodes. Ordinarly, an angiospermous tree sufficiently resistant 

 to fire could supply one or two branches in any given region of 

 the trunk where the conifer could produce a larger number. 

 In the former, it would mean that so far as reproduction and 

 maturity are concerned, a tree burned to the ground has to 

 start over; an injury sufficient to destroy an angiospermous tree 

 leaves unharmed the trunk of the conifer, and the young 

 branches of the conifer find their lines of supply still highly 

 organized. The high pitch and other organic content in the 

 conifer is also of advantage, for such under influence of high 

 temperatures readily carbonizes, and forms a protective layer 

 readily resisting the encroach of the destroying heat. These 

 facts seem to have a direct relation to what we believe to be 

 the conditions under which conifers evolved, and to their 

 persistence in geologic time. 



