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ARTIF IC lAL PARTHENOGENES IS 



Cortical stimulation . Gently but firmly prick each egg with a sharp point of a 

 glass or platinum needle. The puncture should he applied within the animal 

 hemisphere but not in its exact center where the second maturation spindle la 

 likely to be located. Leave the eggs in row "C" untouched as controls. 

 Immediately after pricking the experimental row of eggs, immerse the slide in 

 Spring Water or Standard Solution in which normal development la known to occur. 

 It is best to use Petri dishes and only about 2 cm. depth of medium to cover. 

 Eepeat the above procedure with h other slides from the moist chamber. 

 Follow the above procedure with the remaining 5 slides from the moist chamber 

 but limit the pricking to the vegetal hemisphere of the egg. Mark these slides 

 to Indicate location of stimulation. 



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If time permits, the same procedure should be followed with single variations which 

 might increase the incidence of successful stimulation. Such variables are as follows: 



h. 



Allow the eggs to remain within the uterus at IQOC. for 5 days before stripping 

 (Zorzoll and Rugh, 19^1). Such aged eggs must be allowed to come to the labora- 

 tory temperature before stimulation. 



Keep the female at refrigerator (l4-°C-) temperature, and in the moist chamber 

 provided with ice cubes, to determine whether a lower temperature alone would in- 

 crease the sensitivity of the egg to artificial stimulation. 

 Omit the use of blood or serum (Guyer, 1907; Bataillon, I9II and I919). 

 Vary the depth of cortical Injury, deep or shallow pricking. 

 Allow the eggs to dry (partially) on the slide before pricking. 

 Allow the jelly to swell in water to various degrees, before stimulating. The 

 cortical pricking will be a bit more difficult through swollen jelly. 

 Follow the artificial stimulation of the egg by immersion in media of various 

 osmotic conditions. 



Determine the role of the presence and the absence of calcium (using oxalates and 

 citrates) in the response to parthenogenetic stimulation. 



OBSERVATIONS AND TABULATION OF DATA: 



Record the data from your experiment in tabular form as follows: 

 CONDITION NUMBER & PERCENTAGE 



Total experimentala should include all eggs stimulated. The paeudo- cleavages in- 

 clude irregular cleavages and superficial indications of attempts at cleavage. Along with 

 this data, include a statement regarding the exact method of stimulation. Instrument used. 



