492 FOOT. [Vor XIV. 
safely oriented on the slide by using a single hair inserted in 
the regulation needle holder. 
The general distribution of this material and the possibility 
of studying the whole egg under a high magnification make 
it of especial value for class work, and I publish the above 
detailed description of obtaining and mounting the whole eggs, 
in response to requests from those who wish to use them for 
demonstration in the class room. For the present, however, 
I reserve the publication of my methods of imbedding and 
sectioning. 
As only a few hundred eggs can be collected each year, the 
time required for obtaining all the successive steps in the 
development is necessarily prolonged and uncertain, and I 
shall fill later such gaps as I am now obliged to leave. In 
the present paper I shall briefly state a few of my earlier 
observations. 
OBSERVATION ON THE LiIvinG Eac. 
(Zeiss 0b. 10 to hom. tmmer. 2 mm. 140 ap.) 
The egg must be removed from the albumen in order to 
study it with high powers. Distilled water (a few drops), with 
as much of the albumen dissolved in it as is consistent with 
preserving the necessary degree of transparency, has proved 
the least injurious medium for examination. In this the eggs 
have grown and developed normally from 30 to 60 minutes. 
The normal condition has been tested by removing the eggs 
from this medium, at definite periods of time, killing, imbed- 
ding, and sectioning them for comparative study. The following 
phenomena have been seen in the living egg: the maturation 
spindle in the unfertilized egg, and an indication of the rays 
of its attraction-sphere ; the fertilization of the egg, z.e., the 
appearance of the cone ; the constricting off of the first polar- 
body, and the subsequent disappearance of the cone ; the con- 
stricting off of the second polar-body, and the appearance of the 
polar rings. Not all these phenomena, however, are seen in 
any one egg; for the artificial conditions in which the egg 
must be studied soon arrest normal development. The first 
