44 s Dr. Johnson’s observations on the genus planaria. 
being naturally or artificially divided, to which we shall soon 
advert, or their losing this tube, which was not unfrequently 
the case, they took their usual sustenance by the mouth. 
I should not have entered into this detail, were I not ap- 
prehensive that I should be considered as labouring under 
some mistake, since it seems so contrary to the generally 
established law of nature, that an animal, furnished with a 
proper mouth, should receive its food by another organ, and 
that organ placed as near to the tail as to the head. Such, 
however, is the case ; and the proofs advanced, will, I trust, be 
sufficiently convincing. In addition, I have to observe, that 
Muller, after alluding to this organ, in his description of the 
P. lactea, says, “ Organum hoc nutrimento capiendo inservire 
vix dubitari potest. * ’ 
Although I have repeatedly seen the young of the P. torva 
and P. cornuta, I have not yet been able to determine whether 
they are oviparous or viviparous, which I conceive to have 
arisen from having begun my enquiries late in the season. 
With respect to the P. lactea and P. brunnea , they are ovi- 
parous, producing eggs, within a membranous capsule, each 
capsule containing (at least those of the P. lactea), from 3 
to 8 young. 
One of the P. lactea deposited a capsule, July 8, which, on 
the 10th of August (33 days), produced 8 young. 
Considering the size of the P. lactea , the capsule is of great 
magnitude, occupying nearly one-fourth of the body, forming 
a remarkable protuberance on the back. (fig. 5). 
Six capsules were deposited by the P. brunnea, August 12, 
but of a size much less than those of the P. lactea ; one only 
was productive ( September 5th ) ; it contained 2 young. 
