34° The Ohio Naturalist. [Vol. V, No. 7, 



out these problems is a slow and difficult process as the writer 

 has discovered from experience. 



Finally a word may be added as to the significance of reduc- 

 tion and conjugation in the origin of species. The mixing of 

 protoplasms with diverse hereditary characters must cause a 

 great disturbance in the hereditary apparatus. We may think 

 of a struggle of two characters one against the other, the one 

 becoming dominant and the other unable to reassert itself. We 

 may picture to ourselves the powerful stimulus of the one on the 

 other and the reaction and rearrangement of the material mosaic 

 which may result in the evolution of a monstrosity or a new 

 species. But crossing must after all tend to uniformity. It is 

 the origin of sexual barriers and the barriers induced by the 

 activity of one hereditary tendency over another which has led 

 to diversity in plant and animal life so far as this has any relation 

 to the sexual process. Variation and diversity of type is just as 

 prominent a characteristic of nonsexual as of sexual organisms. 

 The new forms resulting from near or distant crosses must be 

 regarded as merely incidental in the great process of the evolu- 

 tion of the diverse life of the earth, the real and fundamental 

 cause lying in the nature of protoplasm itself whether of sexual 

 or nonsexual organisms. Variation is a property of protoplasm 

 and reproduction is primarily a matter of assimilation and 

 growth. If sexuality were the primary cause of variation we 

 would logically have to suppose a multitude of sexual races in 

 the beginning rather than a simple nonsexual and uniform group 

 of organisms which has evolved and segregated into new types 

 without any special reference as to whether the units in the 

 process have acquired sexuality or having acquired it once have 

 lost it again in ages past. 



A LIST OF OHIO PLANTS WITH COMPOUND LEAVES. 



Walter Fischer. 



In making out a list of plants having compound leaves, a few 

 words on this subject and on the light relation of plants in general 

 may not be out of place. 



From what is known of the function of leaves it is evident 

 that with the exception of plants in xerophytic conditions, the 

 greater the surface exposed and provided this is done in such a 

 way as not to handicap the plant in other ways, the better will 

 that plant be enabled to survive in its struggle for existence. 



Plants may secure a better exposure to light and air in any 

 of the following ways: 



1. By motile leaves and 'stems. 



