^jouS,STi^^^^^^^^ On the Ovum of the Pike. 185 
definite or a detailed description.* For the first time there were 
sixteen species of carboniferous Hmestone Foraminifera unexpectedly 
making their appearance in mineral veins, three of which had lived 
on to the present day, in addition to the liassic forms previously 
enumerated from Charter House. 
In addition to the Microzoa mentioned above, I may remark 
that from veins and fissures of different ages in the Carboniferous 
Limestone I obtained remains of the oldest known Mammalia, the 
oldest land and fresh-water mollusca, about 32 species of fish and 
eight of reptilia ; so that altogether, under these peculiar circum- 
stances, I have found about 267 species. 
III. — Ohservations on the Developnent of the Ovum of the Pike. 
By E. B. Truman, M.D.t 
Plates XXVIII., XXIX., and upper half of XXX. 
In the spring of 1866 I was engaged in watching closely the 
wonderful and beautiful changes that take place in the egg of the 
pike of our rivers, which have for their end the development of an 
immovable, transparent gelatine-like ball into the most lively, 
active, and voracious pike, the king of our fresh-water pools and 
streams. I do not propose to go at any length into the minute 
anatomical changes which I witnessed, nor shall I permit myself 
more than is quite unavoidable the use of technical language. I 
intend here to relate the method of obtaining the supply of eggs, of 
keeping them alive, and of watching them ; and in a general way, 
the interesting and remarkable sights that are to be seen in a study 
of this kind. The circulation of the blood throughout a hundred 
httle veins and arteries, the beating of the fountain of life from and 
to which they pass and return, the growth and formation of the 
brain, the eye, the ear, and of the viscera, and many other marvellous 
processes may be viewed by any one who possesses a microscope and 
a supply of eggs. My purpose is to narrate what I saw, so that 
others may look for themselves. 
In order to obtain a supply of eggs, the pike of both sexes must 
* It is a very interesting fact, that within the last few days a bed of Mountain 
Limestone, of considerable extent and thickness, has been found on the estate of 
Sir Walter Trevelyan, formed almost entirely of this organism. Whether the 
fossil really belongs to Lituola, or may not yet be another phase of that wonder- 
fully polymorphic type Involutina, is a point upon which my friend Mr. Brady is 
at present engaged. 
t The writer desires to state that this paper was originally written for a 
periodical of a popular character. This will account for many details or explana- 
tions in the text which will be unnecessary to the scientific reader. 
