THE ORIGIISr OF LIFE ARMSTRONG. 541 



in directing the growth of the organism. Tlie cell, in other words, 

 is the unit factory and its definition should be made independent of 

 microscopic appearances. 



To conclude: All speculation as to the origin of life must savor 

 of the academic; it can liave no very definite outcome unless it be 

 verified experimentally, and at present it seems improbable that 

 such verification will be possible. But speculation is none the less 

 legitimate and desirable on account of the fundamental issues to 

 be considered. 



In discussing the problems of heredity, in deahng with disease, we 

 are groping in the dark so long as we are ignorant of the precise 

 nature of the vital processes and of the minute details of organic 

 structure; no effort should be spared, therefore, to unravel these. 

 The results of modern cytological inquiry are very marvelous but 

 unsatisfactory. We need to know far more of living material, 

 especially in the vegetative stage; the chemist has difficulty in 

 accepting the fincHngs of the morphologist at their face value; he 

 can not avoid the feehng that not a few of the ''structures" described 

 may be artefacts bearing but a cUstant resemblance to the hving 

 forms, as structure is usually brought into evidence by staining and 

 this can not take place until the chfferential septa of cells are broken 

 down and rendered permeable ; so that the staining and fixing process 

 is one that must be attended with chemical changes, among wliich 

 coagulation effects are to be reckoned. But the appearances in 

 many cases are too definite, too wonderful, to be mere artefacts. 



What is now needed is the combination of the eyes of the cytologist 

 with those of the chemist and with those of the physiologist, the 

 collaboration of the student of external structure, and the student 

 of function. Continued speciahzation can only carry us farther away 

 from the goal we are all striving for, though vaguely, because we have 

 no settled combined scheme of action. 



