332 
G. DEBAISIEUX. 
those obtained by other experimentalists^ but in most of the 
experiments the question of dominant characters was not 
considered, and the examination of their works would go 
beyond the limits of this paper. I will simply say that my 
conclusions agree with those of Loeb, King and Moore (^10), 
of Moore (’12), and of Tennent (’10). They would also 
probably agree with those of Veiuiou (’00), Doncaster (04), 
and Herbst (’06, ’07). 
It only remains for me to speak of the difference which 
exists between the results of my experiments and of the 
earlier experiments of Shearer, De Morgan, and Fuchs (’ll), 
'riiis year these authors obtained results which are partly 
opposed to the results they had obtained in former years, and 
which, as far as I can judge from their preliminary notes 
(‘Nature,’ June 27th, 1912) are fairly analogous to the results 
which I am now describing’. They believe that this differ- 
ence is due to the fact that certain external circumstances 
affect the sexual cells of Echinus mi liar is. 
It seems difficult to admit this hypothesis because, contrary 
to their observations, I have noticed that the eggs of E. 
miliar is x miliar is which developed were relatively more 
numerous than the eg’gs of E. acutus x acutus; and that 
the larvae of E. miliar is x miliar is were very easy to 
rear; in the same way the larvae of miliaris ? x 
acutus were relatively more numerous than those of 
acutus ? X miliaris If one studies the question 
with regard to the dominant characters, one comes to a con- 
clusion which is quite opposed to the one given by these 
authors. 
In their account of this year’s experiments one notices 
that these authors deal with two dominant characters (pos- 
terior epaulettes and posterior pedicellaria) belonging to E. 
acutus and one recessive character (green pigment) belonging 
to E. miliaris. In the experiments of former years these 
dominant characters were not transmitted by the sperm of 
E. acutus, nor was the reces.sive character crushed by the 
action of the sperm of E . acutus. It appears, therefore. 
