4 CALIFORNIA ACADEMY OF SCIENCES. 



that in order to convey a proper understanding of the 

 subject I cannot do better than r^uote his words in full. 

 It is stated in the following seven assumptions: 



" 1 . That all the component cells of a multicellular or- 

 ganism throw off inconceivably minute germs or "gem- 

 mules," which are then dispersed throughout the whole 

 system. 



2. That these gemmules, when so dispersed and sup- 

 plied with proper nutriment, multiply by self division, 

 and, under suitable conditions, are capable of develop- 

 ing into physiological cells like those from which they 

 were originally and severally derived. 



3. That while still in this gemmular condition, these 

 cell seeds have one for another a mutual affinity, which 

 leads to their being collected from all parts of the system 

 by the reproductive glands of the organism; and that, 

 when so collected, they go to constitute the essential 

 material of the sexual elements — ova and spermatozoa 

 being thus nothing inore than aggregated packets of 

 gemmules, which have emanated from all the cells of all 

 the tissues of the organism. 



4. That the development of a new organism, out of 

 the fusion of two such packets of gemmules, is due to a 

 summation of all the developments of some of the gem- 

 mules which those two packets contain. 



5. That a large proportional number of the gemmules 

 in each packet, however, fail to develop, and are then 

 transmitted in a dormant state to future generations, in 

 any of which they may be developed subsequently — thus 

 giving rise to the phenomena of reversion or atavism. 



6. That in all cases the development of gemmules 

 into the form of their parent cells depends on their suit- 

 able union with other partially developed gemmules, 

 which precede them in tlie regular course of their 

 growth. 



