i66 



The Journal of Heredity 



as well as reduplications. Eyes may be 

 lacking or reduced in size on one or both 

 sides and in one case a small extra eye 

 Avas located on the cheek and connected 

 "with the normal large eye by an isth- 

 mus. Occasionally the compound eyes 

 may be fused into one, obliterating 

 the ocelli, or the ocelli may be lacking 

 AV'hile the head appears otherwise 

 normal. 



Antennae vary slightly in number of 

 joints, shortening being correlated with 

 small size of the body as a whole. 

 Abnormalities of antennae include 

 branchings of various types, as well as 

 extreme shortening, or failure to appear 

 at all on one or both sides. 



Females normally have one pair of 

 ■elongate sensory gonapophyses in addi- 

 tion to the sting. An additional gona- 

 pophysis of var^'ing shape not infre- 

 quently appears on one or both sides, 

 or one of the pair normally present 

 may be misshapen. 



Wings vary occasionally in number 

 of veins both by addition or extreme 

 reduction. 



Not infrequently the external genita- 

 lia of males or females may be much 

 reduced or lacking altogether. There 

 may likewise be complete failure of the 

 midgut to connect with the hindgut 

 and Malphigian tubules may be much 

 reduced in length or lacking altogether. 

 Defects in hindgut are correlated with 

 ■defects in genitalia, the abnormalities 



Corrections in Previous Articles 



The description of "A Living 

 Double-headed Calf" in the Journal 

 for May 1921 contained the statement 

 (page 239) that: "The upper jaw-bones 

 of each mouth seem quite normal 

 €xcept for the absence of the front 

 teeth." 



Cattle breeders and (jlhers interested 

 in genetics desire to censor that state- 

 ment for very obvious reasons! The 

 Journal is pr()m[)t to acknowledge the 

 correctness of their challenge. From 

 the fact that the calf's head contained 

 so many abnormalities it is assumed 

 that the observer did not expect to 

 find any normalities, and the misstate- 

 ment was passed unnoticed by subsc- 



being due apparently to general growth 

 conditions at the posterior end of the 

 abdomen. Transverse abdominal scler- 

 ites may be irregularly arranged, failing 

 to extend across the back in some cases. 



None of these growth abnormalities 

 hasyet proved tobe hereditary, although 

 all types have been tested with the 

 exception of defecti\'e genitalia. 



I">om the abo\-e account of breeding 

 work with Hadrobracon, it may be 

 seen that while the species is somati- 

 cally very variable, it is genetically very 

 stable. Only two genetic differences 

 have been found and one of these affect- 

 ing the venation was deri\'ed from wild 

 stock. Orange eye color occurred as a 

 mutation in the laboratory. It is 

 much to be hoped that future studies 

 will disclose further mutations which 

 may be used for analysis of genetic and 

 ontogenetic mechanics. 



The writer has been aided much in 

 the work by Mrs. Whiting. He is 

 indebted to the American Association 

 for the Advancement of Science for 

 research grants to purchase equipment 

 and supplies. He also wishes to express 

 gratitude for laboratory facilities pro- 

 vided at Woods Hole and Cold Spring 

 Harbor. Samuel B. Doten of the 

 University of Nevada has assisted 

 much with suggestions in regard to 

 technique and with photographs of the 

 living insects. 



quent readers of the manuscript imtil 

 it boldly presented itself on the printed 

 page. 



In the Journal for April 1921, the 

 designations of Daturas (Fig. 16) in 

 the text on page 190 should be reversed 

 from the order in which they appear, 

 that is. No. 1 should read No'. 4; No. 2 

 should be No. 3; No. 3 should be No. 1 ; 

 and No. 4 should be No. 2, of D. 

 pittieri (not rosei as printed). 



In the article "Education and the 

 Size of Families" (April 1921, page 190) 

 the statement "co-educational col- 

 leges" should read "men's colleges." 



