TILE EXrERIMENTAL IIYBUIDIZATION OF ECHINOIDS. 



1 1 K 



cross the characters comiuon to E. acutus and E. escukntm make 

 their appearance. 



SUMMARY OF LATE LARVAL CHAKAC 



Considering only these six external characters the experiments of 

 1010-11 show that:— 



1. The egg of Echinus csmlentns fertilized by its own sperm pro- 

 duces a late larva having anterior epaulettes, posterior epaulettes, no 

 green pigment, one right side dorsal pedicellaria, one right side ventral 

 pedicellaria, one posterior pedicellaria. 



2. The egg of Echinus escu/entns fertilized by sperm of Echinus 

 miliaris p^roduces a late larva having anterior epaulettes, posterior 

 epaulettes, no green pigment, one right side dorsal pedicellaria, one 

 right side ventral pedicellaria, one posterior pedicellaria. 



These characters are the same as 1. 



3. The egg of Echinus miliaris fertilized by its own sperm produces 

 a late larva having anterior epaulettes, no posterior epaulettes, green 

 pigment, one right side dorsal pedicellaria, one right side ventral 

 pedicellaria, no posterior pedicellaria. 



4. The egg of Echinus miliaris fertilized by sperm of Echinus 

 csculcntus produces a late larva having anterior epaulettes, no posterior 



