314 MAINE AGRICULTURAL EXPERIMENT STATION. I916. 



the distance from the origin to the mid-point of the segment is 

 of the whole length of the line. An egg then has a definite 

 clutch position value expressed as a fraction of the clutch. 

 These values are comparable for all sizes of clutches. For 

 example, the value assigned to the middle egg of any clutch 

 which contains an odd number of eggs is .500. A table was 

 calculated which gives the value for each clutch position in 

 each size of clutch. By means of this table the clutch position 

 for each dwarf egg can be determined in terms which are com- 

 parable for all cases of dwarf egg production whatever the size 

 of the clutch. 



The clutch position frequency for the occurrence of dwarf 

 eggs is given below. 



Fraction of clutch. Dwarf egg frequency. 



0-.199 19 



.200-. 399 40 



.400-.599 25 



•600.799 35 



.800-.999 28 



147 

 Mean = .518=^.015 

 Standard Deviation — .26y±.oii 



This distribution is shown graphically in Fig. 55. 



In this case as in the case of litter position the irregular 

 fluctuations are not greater than would be expected to occur 

 from errors of sampling. 17 The present data indicate then that 

 a dwarf egg is equally likely to occur in any clutch position. 



IX. Physiological Conditions and Effective Stimuli 

 Which Lead to Dwarf Egg Production. 



It has been shown that dwarf eggs usually represent some 

 temporary disturbance or some accident in the physiology of 

 reproduction since such eggs are preceded and followed by 

 normal eggs. The disturbance is most likely to occur during 

 the height of the breeding season although it may happen at 



"For mathematical proof, see original paper. 



