264 PHILOSOrHICAL NOTES OX 



into an anther and the other into a stigma, much as we see them 

 in the Canna, while {e, e), are bud-scales of the tw^o leaves, or 

 branches as we may choose to call them. 



An ovule appears to be the terminal bud of the vein, or branchlet 

 that feeds it,^ in the same way that the bud at the apex of a 

 branch is the terminal bud of the stem ; or the axillary bud is the 

 terminal bud of a branch of the petiole. 



The ovule of the Yew is surrounded by an aril, which appears 

 to be only a fusion of bud-scales, like the disk of a flower. What 

 does it signify that the aril grows aftej- the ovule is fertilized ? 

 That may be only a matter of convenience, and a variation 

 connected with natural selection. 



We see that, according to Penzig, the scale of the Citrus 

 axillary-bud develops into a spine long before the bud itself 

 makes any attempt to develop, and often the spine is the only part 

 of the axillary l)ud that does develop, the bud itself remaining 

 abortive. 



It is usual to consider the arillus of the Yew as a growth from 

 the disk, which surrounds the ovule. But what is this disk ? It 

 is probably an abortion of stamens, like that of the orange, the 

 preony, the rhododendron, and others. Stamens are leaves, and 

 leaves are bracts. So we may call the arillus at once a whorl of 

 fused bracts, serving a special purpose. If they are bracts, the 

 reader might ask, why have they not grown simultaneously with 

 the outer bracts ? There may have been good reasons for this. 

 It was necessary that the ovule should be at first naked, to 

 facilitate fertilization ; after this had happened, the aril began to 

 develop, but it was important that the ovule should not be 

 advertized till it matured, and therefore in the first stage, the 

 aril was green, and indistinguishable from the leaves ; in the 

 second stage, it l)ecame of a bright rose, and sweet to attract 

 the attention of birds, and invite them to eat it, and so help to 

 disseminate the seed. 



The disk is nothing but a fusion of abortive stamens, or nipples 

 of other phvllous organs. It is, therefore, no absurdity to consider 

 the arillus of the Yew as a fusion of bud-scales, AVe see similar 

 fusions of bud-scales occurring elsewhere. 



* Veins ajid voinlots hci?)'; onlv tlio ultimate suh-divisions of branches. 



