342 Journal of the Asiatic Society of Bengal. [N.S., XVI, 
g.1) thus obviating any risk of dryness. A piece of wide- 
etal muslin was tied round the mouth of the pot, and the 
water in the bowl was renewed every day. e number of 
cocoons laid bya single leech during the period varied from one to 
four, viz., one cocoon by ten specimens (Nos. 4 7, aU, ad, bo ae, 
23, 24, 25, 26, 31), two by ten (Nos. 1, 5, 7, 14, 16, 18, 22,27, 
29, 30), three by two (Nos 8, 12), and four by one specimen 
(No. 19). 
In a previous lot of six specimens kept under observation 
from May 7, two freshly laid cocoons were found on May 13, 
another on May 15, two more on May 26—making a total of 
In all, forty cocoons were laid by twenty-two specimens, 
five leeches (Nos. 6, 21, 28, 32, 33) having died without laying 
cocoons, another (No. 18) after laying two cocoons, = six 
leeches (Nos. 2, 3,9, 11, 20, 34) did not form cocoon 
The cocoon during its formation dome as a ube frothy 
girdle round the middle of the body (fig. 1). The animal slowly 
withdraws its head through the ‘girdle ty rhythmic contrac- 
tions of the body. The right and left sides of the anterior 
region are alternately raised up and every time the body i is bent 
dorsoventrally. The body of the leech behind the region of the 
cocoon-formation remains considerably contracted during the 
rocess. When the head is completely withdrawn an opening 
is ve at the anterior and posterior ends, which soon close up. 
Cocoon-laying is a comparatively slow process lasting for at 
eras six hours (figs. 2 and 3). 
In the freshly laid condition the posterior part of the 
eres (fig. 3) is broader than the anterior and notched in the 
iddle. Inaday or two the cocoon hardens, when it assumes 
an oval shape (fig. 4) measuring 18-20 mm. in length and 11- 
m. in breadth. The cocoon-wall consists of an inner 
plug. When placed in water a cocoon igti: but if t 
spongy outer layer is scraped off it 
n May 25 the water in the pots was not renewed, a 
as a result much of the water in the pots had syapordad 
by the following day, the earth in some having become almost 
dry. On examination on the 26th May, a newly laid cocoon 
was found in the pots containing leeches Nos. 5, 7, 12, 16, 18, 
19, 22, 25, 26, and 29, whilst the leeches Nos. 6, 21, 28, and 32 
were found dead, owing perhaps to dryness. The temperature of 
room on that day was 32°C, whilst that of the moist earth in- 
side the pots was 24°C. Fresh water was then poured into 
cocoons were found, owing perhaps to the return of favourable 
conditions such as sufficiency of water, coolness, etc. 
