348 



STEFAN KOPEC. 



segregated in respect to sex. Further and more detailed research 

 ought to be undertaken in this respect. 



It ought to be remarked, that notwithstanding such distinct 

 influence of both thyroid and Lugols' solution on growth of 

 caterpillars, mortality in the animals of the experimental ma- 

 terials was in general not larger than in those of the control. 

 The average mortality in male "thyroid" larvae attains ca. 6 

 per cent., in females 5 per cent., in the control materials 4 per 

 cent, in males and 7 per cent, in females. Analogous data for 

 "thyroid" chrysalids was 7 and 3 per cent., in control pupae 6 

 and 2 per cent. The larvae of Pieris brassica reared as a rule 

 very badly in the extremely damp air under glass, but also here 

 no specially negative influence of the experiment could be 

 observed. Viz. the average mortality in the "iodine" cater- 

 pillars was here approximately 43 per cent., in the control 

 material 38 per cent. 



TABLE v. 



THE COEFFICIENTS OF CORRELATION BETWEEN THE WEIGHT OF CHRYSALIDS OF 

 Lymanlria dispar L. AND THE LENGTH OF THE LARVAL PERIOD. 



r E T , coefficient of correlation together with its probable error; r/E r , ratio of 

 the coefficient to its probable error. 



After the present experiments were finished an abstract 

 appeared ' referring to a recently published preliminary note of 

 Terao and Wakamori ('24) inaccessible to me. The authors 

 report that the metamorphosis of the caterpillars of Bombyx 



1 Berichte it. d. ges. Pysiol. u. exp. Phtirmak., Vol. 28, p. 119, November 12, 1924. 



