ARTIFICIAL PARTHENOGENESIS AND HYBRIDIZA- 

 . TION IN THE EGGS OF CERTAIN 

 INVERTEBRATES 



MAX MORSE 



Trinity College, Hartford, Connecticut 



INTRODUCTION 



The experiments described in the following pages are to be 

 placed in three divisions : 



1. Experiments in the production of polar bodies and cleavage 

 in Cerebratulus by artificial means. 



2. Experiments relating to artificial hybridization between 

 Cerebratulus and certain other invertebrates, wherein the com- 

 bination of the power of the spermatozoon of the foreign animal 

 and of the efficient parthenogenetic reagents discovered in the 

 first set (1) of experiments was utilized, to induce hybridization, 

 where the influence of the sperm alone was found to be inefficient. 



3. Experiments which may be described as by-products of 

 the principal work, such as the followjing: (a) Effect of sperm 

 extract; (b) Effect of the phospholipine, 'lecithin' in inducing 

 changes in unfertilized eggs of Arbacia; (c) Role of hydrogen 

 and hydroxyl ions in artificial parthenogenesis. 



The conclusions which seem to be valid from these experi- 

 ments are as follows: 



1. Cerebratulus lacteus and marginatus resemble several other 

 invertebrates in their refractoriness in response to reagents which 

 readily induce artificial parthenogenesis in certain forms of 

 animals. 



471 



