Identity of Anagallis arvénsis and cerilea. 537 
they may be truly accounted the most ancient vessels in the 
world, because their forms, and materials, and equipments, 
have remained unaltered since the times of the earliest histo- 
rlans. Yours, &c. 
July 31. 1830. Joun Hoge. 
Art. XI. On the Specific Identity of Anagallis arvénsis and 
caerulea. By the Rev. J. S. Henstow, Professor of Botany in 
the University of Cambridge. 
Sir, 
Dr. Hooxer, in his most excellent British Flora, still 
keeps the Anagillis caerulea distinct from the 4. arvénsis ; and 
perhaps the difference pointed out by him in the shape of the 
petals fully justifies him for so doing in the present uncertain 
state of our knowledge of the laws which regulate the limit- 
ation of species. J received last year, from the Reverend E. 
Wilson, some specimens and seeds of Anagallis czertlea 
gathered in Yorkshire. From these seeds I have raised a 
dozen plants, nine of which have blue flowers, and three have 
red. Hence it should seem that in future Anagallis ceertlea 
must be considered as a variety of 4. arvénsis. I conclude, 
from the above fact, that whatever may be the cause which 
disposes the petals of this species to assume a blue colour, 
this likewise disposes them to become notched or toothed at 
the margin, as Dr. Hooker has universally observed them to 
be. Though we cannot say the following law is certain in 
botany, yet it seems to me very likely to be true, viz. * That 
if a change takes place in one of the organs of a plant, a simul- 
taneous change may be expected in some or all of the other or- 
gans considered to be modifications of the same organs.” or 
instance, considering the calyx and corolla to be modifications 
of the leaf, when we see the leaf of the cowslip differmg from 
that of the primrose, we need not be surprised to find that 
the calyx and corolla should differ also, though these plants 
be not distinct species, as I showed in my communication to 
the last Number of your Magazine. 
I have met with the light pink variety of A. arvénsis at 
Higham, Kent; and the gentleman from whom I received the 
seeds of the blue variety mentioned in this communication, 
sent at the same time, and from the same place, some seeds 
of a white variety, similar to that received by Dr. Hooker 
from South Wales. From these seeds I have raised seven 
Von. III. — No. 16. NN 
