OKLAHOMA ACADEMY OF SCIENCE 151 



creation; maybe it was travelling all this time, since the beginning 

 of the world, and has not come to earth yet. Can't It be, mamma?" 

 A.'s h>potheses fall into two groups: those which he himself 

 knows to he hypothetical, and those which he thinks are truths. 

 These Salter are beliefs and conceptions based on mistraderstood in- 

 formation. The man-in-the-moon theory belongs to the second 

 group, while that about the sounds from the stars is a real hypo- 

 thesis. 



XXXIV. A COMPARISON OF THE SIZES OF THE 



VOCABULARIES OF FTFTY CHILDREN OF THE 



SAME AGE 



Miriam E. Oatman-Blachly 



Norman, Oklahoma. 



For several years I have been collecting the vocabularies of 

 children at the age of eighteen months. Tt was my hope that a care- 

 ful s^udy of such vocabularies might throw some light upon several 

 problems of child psychology and education, such as : A child's 

 earliest interests ; the normal range of vocabulary among normal 

 children of the same age; and the differences between the sexes, if 

 such difference exists in the matter of speech development. 



I have now collected fifty-one of these vocabularies almost 

 evenly divided between the sexes. My friends have helped gener- 

 ously in gathering the material ; and 1 am especially indebted to 

 Mrs. Margaret Morse Nice, who has made so many interesting 

 and valuable studies of the speech development of children. It is 

 not my purpose at this time to make an intensive study of the con- 

 tents of the voacbularies, but to examine their size, and to see if 

 any deductions can be dravv^n in regard to the average or normal 

 number of words of boys and girls at the age of eighteen months. 



My material arranges itself as follows : 



Cases Collected from Published Studies 



Name Sex Source Total Words 



1. Allee Male 11 1 



2. Cary Male 8 60 



3. Gale 2 Male 6 113 



4. Oatman-Blachly 1 Male 1 113 



5. Nice 2 Female 11 



6. Nice 3 Female 11 2 



7. Drummond Female 5 7 



8.- G^le 3--^-:-^-- ^^^^.,^=.=_Female (^ 33 



