1876.] Proceedings of Societies. 509 
through the press, he had remarked -that “at first view it seems singular 
that the eggs of an insect that appears in such countless myriads from 
Maine to Georgia, and from Virginia to Kansas, should have remained 
undiscovered either by farmers or entomologists. One of the obstacles 
that have stood in the way is, that, as soon as the worms have increased 
so prodigiously as to attract attention, their natural: enemies become so 
multiplied that a very small per cent. of the worms entering the 
ground issue again as moths. A second reason is that during the season 
when the insect is not numerous, and attracts no attention, no one thinks 
of searching for the eggs. A third reason is that'the moths that are 
reared indoors do not oviposit in confinement. I venture to suggest a 
fourth possible reason that has hitherto occurred to! nobody: it is that 
the eggs are for the most part secreted where they are not easily seen.” 
Structure is a trustworthy guide to habit, and Mr. Riley had been led 
to this last conclusion by a study of the structure of the ovipositor of the 
moth in question. The time, place, and manner of oviposition in this 
Species is quite important from the economic point of view, as the insect 
may readily be destroyed in the egg state by fire, if the conclusions 
drawn were correct. 
Mr. Riley had recently been able to verify the correctness of his con- 
clusions by direct observation, having witnessed the mode of oviposition 
on blue grass. The eggs are, as he surmised, secreted, being either 
glued in rows of from five to twenty in the groove which is formed by 
the folding of the terminal grass-blade, or in between the sheath and the 
stalk. More rarely they are pushed into crevices in the ground, espe- 
cially at the base of the grass-stalk. The eggs are white, slightly irides- 
cent, spherical, and only +25 of an inch in diameter. They are fastened 
toeach other and to the leaf, and covered along the exposed portion 
by a white, glistening, viscid substance. As they mature the color be- 
comes more sordid or yellowish, and'by the seventh day after deposition 
the brown head of the embryon shows distinctly through the shell. e 
larva hatches from the eighth to the tenth day, measures 1.7 mm. in 
length, is dull, translucent-white in color, with a large brown-black 
ead, and is a looper, the two front pair of abdominal prolegs being 
atrophied. On account of its extremely small size and of the color 
resembling the pale bases of the grass-stalks near the ground, it is almost 
™possible to find them even where there are dozens to the square foot. 
ACADEMY or NATURAL SCIENCES OF PHILADELPHIA. — March 21. 
Dr. Leidy.called attention to a fragment of the lower jaw of a mastodon 
found on the Amazon by Dr. Isaac S. Coates, of Chester. The species 
Was determined to be Mastodon andium. 
Ar. Meehan spoke of the phenomenon of natural inarching among 
He described and explained such an occurrence in the case of a 
hemlock growing in the neighborhood of Germantown. 
Professor Cope placed on record a new type of insectivorous mam- 
mals. It is allied to the extinct rodent-like forms from the Bridger beds, 
