288 Studies in thr Physiohujii of Fertilization 



In the first experiment ilu-ce drops of Strongylocentrotus sperm-sus- 

 pension were added to I'ach of three dishes containing (1) 5 cc. water, 

 (2) 5 cc. Strongylocentvotus etrg-extract, and (3) 5 cc. Ciona egg-extract. 

 5 cc. water was tlien addefi to eacli and they were poured on to three 

 separate equal lots of Strongylocentrotus eggs (see Table XXVIII). 



TABLE XXVIII. (4.2.3.6.) 



SI rotujt/hvfittrtitus Ciona 

 Water extract extract 



Cross: Strongylocentrotus A/h ... 68 87 88 



Both extracts increased the fertilizing power of the sperm In the 

 same extent. 



2. Comparison of the effects of Strongylocentrotus and SphaereclrinKS 

 egg-extracts on the fertilizing power of Strongylocentrotus sperm. 



In each of the two experiments made (Table XXIX), definite equal 

 amounts of Strongylocentrotus spei-m-suspension were added to (1) 5 cc. 

 water, (2) .5 cc. Strongylocentrotus egg-exti-act, and (3) 5 cc. Sphaer- 

 echinus egg-extract. To each was then added 5 cc. water, and they were 

 poured on to three approximately equal quantities of Strongylocentrotus 

 eggs. Each experiment was made doid^le. two different strengths of 

 sperm-suspension being used. 



The results of the experiments aix' given in Table XXIX, which 



shows that both exti'acts increased the fertilizing pnwer of the sperm 



equalh'. 



TABLE XXIX (L30.5.) 



Exp. 1. SiriiiigijhtreiitiotKK ll/f 

 Exp. 2. StroiK.niloccMrotus ll/il 



3. Comparison of the effects of Strongylocentrotus and Echinus egg- 

 extracts on the fertilizing power of Strongylocentrotus sperm. 



In each experiment definite amounts of Strongylocentrotus sperm 

 (see Table XXX) were added to (1) 5 cc. water, (2) 5 cc. Strongylocen- 

 trotus egg-extract, (3) 5 cc. Echinus egg-extract. To each was then 

 added 5 cc. water, after which they were poured on to three approxi- 

 mately equal lots of Strongylocentrotus eggs. 



The results shown in this Table are not sn unifcirm. In the first 

 part of Exp. 1 the Echinus egg-extract raised the fertilization percentage 



