4 University of California Publications in Zoology. VoL - G 



sible throughout the experiments. So large a part of experi- 

 mental work in biology, especially when developmental problems 

 are concerned, is based first and foremost either on an initial 

 mutilation of the organism or a radical disturbance of its natural 

 surroundings, that it seems as though experimentation of the re- 

 verse sort ought to be attempted more than it is. Not that the 

 interference type of experiment should be done away with; but 

 the question of "fair play'' would seem to eome in. The or- 

 ganism ought to have a chance to reveal to us what it dues habit- 

 ually, that is, normally, as well as what it may do under excep- 

 tional circumstances. (2) The other fact to which special at- 

 tention should be called comes out most conspicuously in the last 

 question contained in number 6. i.e., would there be any constant 

 or necessary relation between the rate of loss of weight in the 

 developing egg and the normal length of life of the organism .' 

 The special point here is the closeness with which the whole life- 

 cycle of the organism would be linked together by such an in- 

 quiry. This seems to me important. For a number of years 

 the conception of the "organism as a whole" appears to have 

 been gaining a foothold in biology. So far, however, as I am 

 aware, the idea has had sole reference to the organism at this par- 

 ticular moment or for a particular phase of its life; to particular 

 equilibrational states, as one might say. It has been a spatial 

 matter alone. Now the query is. Is there such a thing for scientific 

 biology as a life-cycle as a whole? That is, are there qualitative 

 and quantitative differentia within the same cycle, and as between 

 different cycles, that one may get at by observation? Can the 

 conception "organism as a whole'' be extended to existence in 

 1 1 an as well as to existence in spaa .' 



The problem certainly deserves wider and more rigid exam- 

 ination than it has had. Despite its obvious complexity it is not 

 altogether unapproachable by experiment, as Minot's work in 

 particular shows, and as does also this little contribution. The 

 conception of a continuous substance known as germ-plasm and 

 held to lie "the carrier" of heredity, has undoubtedly been of 

 great use to biology as a "working hypothesis." I am. how- 

 ever, of the opinion that its day of usefulness has passed and that 

 it is now standing seriously in the way of sound progress. I be- 



