Molecular Structure in Protoplasm 75 



Experimental work is greatly desired which takes the molecular 

 viewpoint into consideration even though the direct purpose of the 

 experiment is based on a higher dimensional level. On the other 

 hand it may be possible that the molecular viewpoint and the sub- 

 microscopic viewpoint, where molecular structure of the particle is 

 taken into consideration, will help to direct the experimental at- 

 tempts to answer the many questions which are constantly arising. 

 Suggestive bits of information come out of the molecular dimen- 

 sional models and also from the conception of cohesion forces in their 

 manner of holding molecules and particles together. This informa- 

 tion seems directly applicable to the materials of protoplasm, for 

 regardless of whether we are dealing with large molecules, with 

 mechanisms, or with the summation of these into a protoplasmic mass, 

 we still are dealing with atoms and atomic groups and with the forces 

 which are involved in their interaction and in the formation of mole- 

 cular structures. Further, the atoms and the molecular groups occupy 

 specific amounts of space which must be reckoned with in their 

 movement within a concentrated mixture, especially when organ- 

 ized to the extent of cytoplasm. 



SUMMARY 



A very short summary may help to point out what we consider 

 to be important in forming conceptions of molecular structure, as we 

 now think of it in protoplasm. Specifically, the atomic radii and 

 their directive valence angles should be the same in vivo as in vitro. 

 They give shape and size to structures on the molecular level and 

 should actively influence structure on higher levels. The primary 

 valence bond may be considered as furnishing the binding strength 

 and closeness of atomic approach necessary to make the molecule 

 an entity. 



The manner of attachment of molecules and particles to one an- 

 other must be the same in the cell as in vitro; that is, by means of 

 H-bridges, ionic and van der Waals' attraction. The H-bridge is effect- 

 ive directly between two atoms of oxygen and nitrogen only. Ionic 

 forces of attraction may be effective in a similar individual manner 

 between oppositely charged groups; and also as a resultant of several 

 or many charges. Thus particles may be held together by several 

 negatively and positively charged atoms pairing up directly and also 

 by the resultant field produced by all of the charges on the particle, 

 within as well as on the surface. Van der Waals' forces act much 

 less locally on a particle; instead, they act more like a diffuse field 



