of Edinburgh, Session 1885 - 86 . 453 
It is well known that in the common British Lumbricus there are 
only three pairs of vesiculae seminales, and two pairs of small 
spherical copnlatory pouches, which are found in the same segments. 
The only exceptions to this rule mentioned by Vejdovsky, apart 
from the present species, are Allolobojohora dhlorotica , which has 
three pairs of copulatory pouches (according to Duges), and Den- 
drobcena , which has only one pair. Dug&s mentions that seven 
pairs of copulatory pouches are not invariably characteristic of 
L. complanatus. He says : — “ Ces series n’ont pas toujours la meme 
etendue, puisque le nombre des v4sicules varie de deux k sept pour 
chaque cot6. Ces differences sont-elles sp^cifiques, comme le pense 
M. Savigny 1 Je crois plutot qu’il faut les rapporter au temps oil 
l’on en fait l’etude : en effet, a mesure que l’^poque de l’accouple- 
ment s’dloigne, le volume de ces organes diminue; les plus extremes, 
aux deux bouts de la serie, s’atrophient les premiers, et il arrive une 
epoque ou Ton n’aper^oit qu’avec peine les rudiments de ces parties 
si saillantes en un autre temps.”* 
It appears to me that the latter supposition is the correct one, 
and that the greater number of copulatory pouches is in all proba- 
bility the typical number in fully-developed specimens. 
I have recently had the opportunity of confirming Dugas’ sup- 
position in a species of Perichceta (probably P. affinis). My 
friend Mr H. E. Barwell, of Manila, kindly forwarded me a large 
number of earthworms from that locality at my request, and among 
them were numerous individuals of this Perichceta , in which the 
copulatory pouches varied in the most extraordinary way in num- 
ber, though not, as far as I could ascertain, in structure. There 
were no other differences in structure between the different indi- 
viduals. 
On the other hand, no individual of the British species of Lum- 
bricus has, so far as I am aware, ever been recorded which possesses 
more than two pairs of copulatory pouches. The number of copu- 
latory pouches present may serve as an indication of specific rank, 
but it is necessary to make use of this character with great caution. 
In the present instance it may be taken for granted that seven 
separate copulatory pouches distinguish L. gigas from most other 
species of the genus. 
Loc. cit., p. 327. 
