3 '< 5 : 8 Mr. Knight on the comparative Influence of 
any considerable difference in the number of offspring of either 
■sex. I am therefore disposed to believe that the sex of the 
offspring is given by the female parent ; and the probability 
of this seems obvious in fishes, and several other species of 
animals which breed in water ; and though the evidence af- 
forded by the facts adduced is not by any means of sufficient 
weight to decide the question, it probably much exceeds all 
that can be placed in the opposite scale. 
In oviparous animals, I have had reason to think the influence 
of the female parent quite as great, as amongst the viviparous 
tribes, though my observations have been more limited, and less 
conclusive. In viviparous animals, the size of the foetus is affected 
by the influence of the male parent, and, in some instances, not 
inconsiderably ; but the size and form of the eggs of birds do 
not appear to be in any degree changed or modified, by the 
influence of the male ; and therefore the size of the offspring, 
at the birth, must be regulated wholly by the female parent ; 
and this circumstance permanently affects the form and cha- 
racter of the offspring. The eggs of birds, and those of fishes 
and insects (if such can properly be called eggs), appear to 
resemble the seeds of plants, in having their forms and bulk 
wholly regulated by the female parent ; but nevertheless their 
formation appears to depend on very different laws. For the 
eggs, both of birds and of fishes and insects, attain their per- 
fect size in total independence of the male, and the cicatricula, 
the vitellus, and the chalazse have appeared (I believe) to the 
most accurate observers, to be as well organised in the unim- 
pregnated, as in the impregnated egg : in the seed, on the 
contrary, every thing relative to its internal organisation 
appears dependent on the male parent. Spallanzani has. 
