CALIFORNIA IN OCTOBER AND DECEMBER. 113 



In addition to the high proportion of females, which supports the 

 theory of somatic mutation, Morgan brings forward another argu- 

 ment. He says that some of these aberrations are so rare that the 

 chance of their appearance in coincidence with chromosome elimina- 

 tion, itself a rare phenomenon, is very remote. 



It is true that Arrtia caia ab. ob-iciira, the creamy aberrations of 

 A. villica and Abraxas (/rdssiilariata ab. nit/ra are very rare, but the 

 majority of the varietal or aberrational forms, which are present on 

 one side of these mosaics are fairly common locally. In the case of 

 some of the captured specimens both forms are known to occur in the 

 locality, from which they came, and in the case of some of the bred 

 ones it is stated that they were bred from a strain in which the 

 aberrational form was known to occur. In these the origin from a 

 binucleate egg, or even by loss of a chromosome, seems more probable 

 than by a fresh mutation. 



The cnridon and ar^ux are omitted from my final count, because 

 they all come from localities where asymmetrical intersexes are found. 

 The intersexes are most likely due to some abnormal arrangement of 

 chromosomes and these apparent somatic mosaics may arise in none 

 of the three ways suggested. Harrison's hybrid Knnotnos cannot be 

 explained by any of the three theories discussed above. He himself 

 regarded it as due to the entry into one ovum of two spermatozoa, 

 one of which conjugated with the ovum and produced the side with 

 hybrid characters, while the other developed alone and produced the 

 side with characters like siibsu/naria. Morgan points out that this 

 explanation is untenable, because the single nucleus with its one x 

 €hromosome would produce female parts, although they would be pure 

 subst'ifnaria. 



Fertilisation of an egg with two nuclei would not explain the 

 absence of qitercinaria characters on one side. Morgan's suggestion 

 that two or more spermatozoa entered an egg and fused and then gave 

 rise to the side with purely paternal characters explains this fact and 

 also accounts for the sex being male, because in that case more than 

 one X chromosome would be present in every cell. 



It is, however, highly speculative, and I do not know "of any 

 .cytological evidence to support it. 



T, H. Morgan and C. B. Bridges : The Orijfin of Gi/nandroiimrpJis. 

 Carnegie Institution of Washington. Publication No. 278, pp. 26-32, 

 p. 69 and p. 93. 



California in October and December. 



By G. B. PEARSON. 

 I have just got back from my fourth visit to Palm Spring this 

 year. My friends are always enthusiastic about this part of the country, 

 with always the chance of getting something rare. We visited there 

 in October from 15th to 18th. My younger and more agile friends 

 went to a canyon five miles away and one of them secured nearly a 

 hundred of the rather rare Si/nchloe califuniica and a number of 

 Catephelis borealis, also rather rare. The common butterfly was Anoaia 

 st)i(/osa. It was flying before sunrise, probably then it was startled. 

 They were feeding on the flowers of a small desert tree and were easily 



