136 ON A NEW CHARACTER IN THE FRUIT: OF QUERCUS, 
wahuensis, A. DC., have annual fruit, and Q. acutifolia, Nee, bien- 
nial, 
Q. scytophylla, Liebm., has annual. fruit, and Q. calophylla, bi- 
ennial, ‘oF 
Q. obtusata, H. & B. (Q. Hartwegi, Benth.), Q.. tomentosa, Willd., 
Q. reticulata, H. & B., have annual fruit, and Q. crassifolia, H.. & B, 
biennial. T 
And above all, the two species before mentioned, Q. Suber, L., and 
Q. occidentalis, Gay, resemble each other so much that for a long period 
they were considered as one... [Conf. Professor Babington’s note on the 
Cork-tree at Summertown, near Cork, Ireland, supra, p. 56.—E».] 
It was only about the end. of my investigation, when I had become 
familiar with minutie in the characters of Oaks, that I could determine 
at sight if a specimen without ripe fruit was annual or biennial... T 
character is so isolated as to be quite, unfit to form the basis:of a good 
natural clasification, and therefore I have only ventured to use it as.a 
paragraph heading for subdivisions of genera or natural subgenera, and 
most. of all for Endlicher’s subgenus Lepidobalanus, which comprises 
the greater part of Quercus, it 
But Oaks give us another character,—one hitherto unnoticed, and 
probably of greater theoretical importance, though it cannot be ascer- 
tained at a glance, viz. the relative position of the atrophied ovules to 
the seed, which is always single, or, if you will, to the ovary. The 
great external resemblance of the acorns of every species of Oak has 
created the mistaken impression, that. an equally strong resemblance 
exists in the interior ; but it is not so, and when the five abortive ovules 
have been sought round that single one which becomes the seed, and 
when one finds how easy is the observation, it is surprising that writers 
have not noticed it before, and do not even allude to it. Even M. 
Schacht,* who has described the young ovules of Quercus Robur better 
than any one else, states when he speaks of the evolution of the fruit : 
“ Scarcely a trace remains of the ovules which are found at the period of 
fertilization.” But in Q. Robur five abortive ovules are always found 
below the seed, which fills the ripe acorn, They lie against the spermo- 
derm among irregular remains of the partitions. Sometimes they are 
as large as a millimetre, and when less, may easily be discerned with 
the naked eye ora weak lens. They are attached under the seed at the 
* Schacht, Beitr. i. p- 87, t. ii. This plate is reprinted in his ‘ Der Baum." 
