THe MuicroscoricAL News 
AND 
NORTHERN MICROSCOPIST. 
No. 36. DECEMBER. 1883. 
HYDRA: ITS ANATOMY AND DEVELOPMENT 
By J. W. DUNKERLEY, F.R.M.S. 
(Continued from page 273.) 
T may be here observed that some writers state that you may 
slit the animal up and lay it out flat like a membrane, etc., 
etc., with impunity, and then very considerately tell us that we 
need not try the same experiments, as they have been demonstrated 
and confirmed. 
My intention to-night is to give the results of a few of my 
experiments. I have already mentioned to you the success I have 
had in dividing Hydrz, which I will now try to demonstrate a 
little more fully in detail by means of diagrams and prepared 
specimens. But before doing so, allow me to tell you what 
experiments have proved to be entire failures on my part in 
reproducing perfect specimens. 
st. Tearing Hydra into minute parts. 
2nd. Crushing Hydra into a pulp. 
3rd. Engrafting the head of one upon the head of another. 
4th. Making two become one perfect animal. 
5th. The cutting of Hydra into forty pieces did not produce one 
single specimen. 
These experiments were all tried at the best season of the year, 
and at the same time I was having very good results from the 
simple division of the polypes, which you will perceive by the fol- 
lowing taken from my notes :— 
On June the 3rd, 1881, at 2-20 p.m., I took H vulgaris, which 
had been well fed, out of the tank, wherein were a number of other 
fine specimens. It was then placed upon a piece of cardboard in 
a drop of water, and when in the contracted state, it was cut with 
a fine scalpel through the mouth and body, but not through the 
foot or disk. 
I succeeded in dividing it into two equal parts, except that I 
VOL, Ill. 
