IOI I 
Multiseriate Ray of the Dicotyledons. 
only as a passing phase in the seedling, and have thereafter only smaller 
multiseriate rays. Others again, such as B. papyrifera (Spach), do not 
normally possess compound rays even in the seedling, but a wound in the 
latter region will recall them. Finally, B. lutea (Michx.) and B, lent a (L.) 
never have them even in severely wounded seedlings. The various species 
of Betula thus exhibit in an admirable manner the loss of compound rays 
and their replacement by those of the multiseriate type. The actual 
breaking up cannot be observed so well as in the forms previously 
described, for the compound rays usually die out rather abruptly. 
Mr. I. W. Bailey, who is now investigating the loss of compound rays, 
finds among other things that the chestnut ( Castanea ), though possessing 
in the adult wood only uniseriate rays, shows undoubted evidence of having 
once possessed compound rays. He also finds that in Castanopsis the 
evidence is even more striking. 
All these examples from the Cupuliferae show that, upon investigation 
in the proper regions, relics in one form or another of a broad-rayed 
ancestry may be found. Nor is the evidence lacking in other groups. 
In the Juglandaceae broad rays have been observed in seedlings of Carya. 
A tangential view of such a ray undergoing division is presented in Fig. 16 . 
It is probable that investigation in the proper regions will also reveal their 
presence in many other families of the Dicotyledons. 
In this connexion the work of Miss Holden 1 on the uniseriate-rayed 
Sapindales is noteworthy. She finds that Aesculus , which is normally 
characterized by the possession of uniseriate rays, may possess rays of 
much larger size in the petiole of the leaf, in the root, and in the reproduc¬ 
tive axis. From these observations she concludes that this simple-rayed 
form is simple not primitively but by degeneration from a broader-rayed 
type. 
Conclusions. 
We have seen that the members of the Ericaceae exhibit in an 
extremely diagrammatic manner the breaking up of compound rays into 
smaller multiseriate ones, and the stages by which typical multiseriate- 
rayed plants completely lacking compound rays in the normal adult wood 
have been derived. Among forms with broad rays the dissection process 
is apparently widespread, being figured in the Casuarinaceae, Proteaceae, 
and Fagaceae, as well as in the Ericaceae. Among plants possessing 
normally only the smaller multiseriate rays the actual process may be 
observed in the regions of retention of ancestral characters, and where the 
actual process is lost, relics are still retained of the broad-rayed ancestry. 
From all sides, then, the conclusion seems inevitable that the multiseriate 
1 Ruth Holden : Some Features in the Anatomy of the Sapindales. Botanical Gazette, ined. 
