384 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 
reversion to possible remote conditions that we get some small glimpses 
of Avliat may have been the state of affairs in primitive times. 
Now, as I consider the Orange peel to be a coalescence of segments 
of the nature of leaves, it is not very difficult for me to try to explain 
the difference in colour of the segments which we occasionally meet 
with. 
A Euonymus may have one leaf yellow and another green ; so can 
the Ivy and others. But we do not know what causes some leaves to be 
wholly yellow ; or if we take parti-coloured petals, such as in the 
Carnation, the Balsam, the York and Lancaster Rose, Tulips, kc, we do 
?aot know what causes certain colours to be aggregated in stripes, or in 
spots, as in some Camellias. 
If my theory of the genesis of the Orange and Lemon peels can " hold 
water," then the same cause, whatever that may be. which produces a 
yellow leaf in the Euonymus may cause a segment of an Orange peel to 
assume a different colour from that of the rest of the peel. 
If we could get a teratological Orange with leaves on its peel, then, 
perhaps, my theory would be on a somewhat firmer basis. 
The nearest approach that I have ever seen to leaves on the peel is 
that shown in the Gardeners' Chronicle of March 29, 1890, page 60. I 
have reproduced it in outline in my " Philosophical Notes," page 349. 
Its peel seems to have given rise to abortive leaves. 
The different coloured stripes on an Orange peel are, however, not the 
most curious features in the Citrus. 
On some Oranges there appears a raised rib, extending from base to 
tip, and of the same colour as the peel. 
This may be caused by the adhesion of a stamen filament to the 
ovary, and as the latter grows the adherent lohite filament takes on the 
colour of the loeel ; and in the mature fruit this filament appears as a 
mere raised rib of the peel. This fact seems to lend support to the 
notion that the peel is of a i^hyllous nature, as the stamens are 
acknowledged to be. 
You will find examples of this adhesion in Risso and Poiteau's mono- 
graph, figs. 16 and 18, Tab. I., which I reproduced in " Philosophical 
Notes," page 354. 
I do not know whether I have succeeded in giving you in any way 
some sort of lucid explanation of the pale stripe of your Orange. 
l^ou may say that all I have written is pure theory. But what is 
a theory ? It is an attempt on the part of the human brain to gather up 
scattered facts and weave them into some sort of organised and intel- 
ligible whole. 
The subject of striping, whether on leaves, petals, or covering of 
fruits, is a difficult one to unravel, and I have given you all there is stored 
in my brain convolutions under this head. 
P.S. — What made me originally suspect that the Orange peel may be 
formed by the cohesion of a whorl of foliar elements indejjendent of the 
pulp carpels was this : — 
In Poona I found a flat Orange called 'Laroo.' It had a large space 
between the pulp carpels and the peel. The means of connection 
