566 General Notes. [ September, 
ured .65X.55, and were quite fresh. The next morning I visited the 
nest, hoping to see the bird and obtain the remaining eggs, but they had 
been removed, probably by the old bird, as the nest was unknown to 
other persons. The nest was built about a foot from the base of a pine 
amongst a clump of those trees, and was about two inches in diameter 
and four in depth, going down through the pine needles to the ground; 
and on a few of the needles the eggs were laid. If I am right in my 
conclusions as to the species, I think that this case must be quite unique 
both in locality and method of nesting. — Frank H. Nurrer, West 
Roxbury, Mass. 
N A TRANSITORY FŒTAL STRUCTURE IN THE EMBRYOS OF SER- 
PENTS AND Lizarps.!— In the prosecution of his studies in biology 
the student cannot fail frequently to meet with structures and organs 
destined to have but a transient existence. A closer insight into the 
nature of these casès reveals the fact that they are naturally divisible 
into two groups. In one group, these structures, although very transient 
in their duration, subserve, while they exist, important functions, and are 
often quite indispensable to the development of the embryo. In the 
other group the most rigorous investigation fails to detect any purpose 
connected with the life of the subject for which they were called into 
existence. They serve only as illustrations of a general plan of de- 
velopment. Such are the rudimentary teeth developed in the jaw of 
the whalebone whale (Balena mysticetus) prior to the appearance of 
baleen plates or permanent teeth, and corresponding rudimentary incisive 
teeth in the upper jaw of the Ruminantia, which are never followed by 
teeth having any functional character. 
To the former group belong all those obvious and essential struct- 
ures in the development-history of the mammalia, including also 4 few 
whose function seems so simple and transient, yet often important, as to 
be frequently overlooked. It is to one of the latter class to which we 
wish to draw the attention of the society. 
It is a fact well known even to common observation that at the end of 
the beak of the feetal chick there exists a sharp process or horn which 
is evidently employed instinctively to break the brittle shell of the egg 
when the chick has arrived at foetal maturity. A very similar structure 
is found on the beak of some of the embryo turtles ; at least in the cee 
Emysaurus in that group of reptiles. In both birds and reptiles it dis- 
appears soon after exclusion from the egg. di 
Somewhat recently, Dr. Weinland, of Germany, claims to have dis- 
covered in all the snakes of that country, and in many lizards, that a 
small, sharp tooth is developed in the premaxillary bone of oS a 
foetus, and thus furnish important aid in its liberation. : 
of Dr. Weinland is quoted by Owen in the last edition of his great 
1 Presented to the Ann Arbor Scientific Society, July, 1876. 
