134 FRANK R. LILLIE. 



vated in the first wave of negativity; this wave may be entirely 

 superficial and activation may thence extend into deeper layers 

 of the cortex. When, therefore, eggs are inseminated in sea- 

 water and then transferred within the first few seconds to the 

 copper sea-water there will be a certain proportion in which the 

 initial reaction has begun, and this proportion will be larger 

 according as the sperm concentration is higher, as actual experi- 

 ments show. The copper will, however, instantaneously check 

 the activation of more fertilizin so that the eggs must operate in 

 the copper sea-water with that portion already activated. 

 Transfers at later stages will be successively less affected by the 

 copper, as successively greater amounts of the fertilizin will have 

 been activated before transfer, until all is in operation. When 

 this point is reached, at membrane elevation, the other events of 

 fertilization proceed as well in the copper sea-water as in normal 

 sea-water. 



If this form of interpretation is correct, we can perhaps see a little 

 farther into the fertilization reaction. If activation of fertilizin 

 follows immediately after agglutination of the spermatozoon to 

 the egg, we would expect in the case of a heavy insemination that 

 activation would have begun in all of the eggs within a few 

 seconds,, say 5 to 10, after insemination, because it is practically 

 certain that in that space of time all eggs will have agglutinated 

 spermatozoa. However, we notice in both of the tables and es- 

 pecially in Table III. that the proportion of eggs that segment does 

 not suddenly rise to normal in a ten-second exposure. In some 

 cases the rise is relatively sudden, as in Table II., in other cases 

 relatively slow, as in Table III., and this corresponds to the 

 physiological condition of the eggs as shown by the promptness 

 of their behavior in normal fertilization. In other words, it is 

 necessary to postulate a latent period after agglutination of the 

 spermatozoon before activation begins, which varies with the 

 physiological condition of the egg. This fact could be brought out 

 only by use of a reagent like copper that instantaneously checks 

 activation. When the wave of activation is begun it spreads 

 flash-like over the surface, though this rate varies also with 

 physiological condition as shown by the relation of the latter to 



