£7. 33.] TO JOHN TORREY. 325 
studying fertilization a little, and have got out pollen- 
tubes of great length; have followed them down the 
style, have seen them in the cavity of the ovary, and 
close to the orifice of the ovule. 
My first views were in Asarum Canadense and A, 
arifolium, where I can very well see the pollen-tubes 
with even my three-line doublet! I have seen them 
finely in Menyanthes; and in the ovary in Chelidonium ! 
Tam lecturing! in a popular and general way en- 
tirely on physiological botany, and offering no encour- 
agement to any to pursue systematic botany this year. 
My great point is to make physiological botany ap- 
pear as it should be, — the principal branch in general 
education. Next year I hope to take up the other 
rane 
I am using the Lowell illustrations (though too 
large for my ena), and am having no additional ones 
made for the college. For siege things I depend 
much upon the hinkchaeed, I have given two lectures 
on the longevity of trees, and have a third yet to give, 
or at least half of another. . . 
The plants from the ee have some done well, 
others poorly. Buckleyas had a hard time of it. 
Many are dead ; none I think will flower this season, 
as they only put out from the root. Diphylleia, Saxi- 
fraga Careyana, a new one like it, also 5. erosa, etc., 
are now in flower. Astilbe is in bud, also Vaccinium 
ursinum. One Carex Fraseri flowered. Hamiltonia 
only starts from the root. 
In 1844, finding he needed more room for his rap- 
idly increasing herbarium, Dr. Gray applied for the 
use of the Botanie Garden house, which since the death 
1 To his college class. 
