DEVELOPMENT OF PERI PAT US NOViE -ZEALANDIiE. 283 
On the Development of Peripatus 
N ovse-Zealandise. 
By 
Lilian Sheldon, 
Bathurst Student, Newnham College, Cambridge. 
With Plates XXV and XXVI. 
In January last, through the kindness of Mr. Sedgwick, 
I received another supply of Peripatus novae- zealandise. 
As before, they arrived in the living condition, and the eggs 
were removed from the uterus immediately after the animal 
had been killed with chloroform. 
The proportion of males was considerably larger than on 
previous occasions, being twenty-two out of a total of forty- 
nine. There were nine smallish females which contained no 
embryos ; and in the remainder, which varied in size from 
about three-quarters to two inches in length, the uteri were 
filled with embryos. The number of embryos in a single 
female varied considerably, the maximum being eighteen and 
the minimum seven. 
Most of the embryos were preserved in corrosive sublimate 
and glacial acetic acid used hot, but the best results were 
obtained from some which were placed for six or seven hours 
in a mixture consisting of equal parts of - 5 per cent, chromic 
acid and 2 per cent, acetic, and afterwards washed in alcohol. 
In this method it is not necessary to prick the egg-shell before 
the embryo is removed to alcohol. After this method of pre- 
servation, which is that recommended by Hertwig for amphibian 
