116 GENETICS IN SWEDISH FINLAD 



the Fimales also corroborate this. And it becomes still more probable through 

 being able to SEILER and DONCASTER prove, that the lepidoptera, contrary to 

 other insects, are heterogametic in the female genus. My experiments to prove 

 the existence of heterochromosomes in anachoreta females, have hitherto led to 

 nothing, and since the summer 1917 I regret to say, that I have not succeeded 

 in getting the necessary material of this species, rare in Sweden and Finland. 



I will only add a few lines about my purely experimental research. 



A small paper in 1916 treats of the dimorphism of the Sphingid larvae, a 

 question much discussed by evolutionists. Through the four possible crossings 

 between imagines, derived from green and black larvae of Chaerocampa elpenor 

 it is proved, that both the forms are isogenic and thus do not possess any selec 

 tional value. The species consequently possesses a factor, which under certain 

 circumstances has the power of producing black pigment in the skin of the larva, 

 under others, however, lacks this power. The said factor is inherited both if 

 it has been activiscd, as is the case with the black larva, or if it remains inactive, 

 as is the case with the green form. The contest about the different value of 

 selection of the different phaenotypes and their phylogenetic age has consequently 

 been a contest about the beard of the pope. 



Since 1914 the author has been working at a mendelian analysis of the 

 lepidopterous formae Spilosoma lubricipeda, intermedia and zatima. Zatima is a 

 strongly, intermedia a weaker melanistic form of lubricipeda, which is yellowish 

 with a small number of tiny little black spots. The melanism is produced by a 

 factor Z, which is homozygotic in zatima ZZ and heterozygotic in intermedia 

 Zz: it fails in lubricipeda zz. But this factor Z is altered in a high degree by 

 a number of polymere factors, which strengthen the influence of Z. If the poly* 

 mere factors are all homozygotic, a ZZdndividual becomes nearly uniformly black, 

 however if they are absent, a zatima may become nearly white with just a few 

 black spots. On the Zz*individuals the influence of the polymere factors is just 

 as strong, while the rare and small black spots in lubricipeda are changed very little. 

 Through the influence of the polymere factors, not yet finally analyzed, a continuous 

 series of phaenotypes is produced, ranging from an almost purely black specimen 

 to a nearly white one. It is of course theoretically possible to receive all these 

 different phaenotypes, which are also different biotypes, in one sole crossing; in 

 fact it has been successfully performed, with the exception of the very rare most 

 extreme forms. A preliminary paper about this research was published in 1920. 



For the sake of completeness I beg to state, that Professor ALEX. LUTHER has 

 examined the heredity of Agriolimax agrestis and Agr. reticulatus and among 

 other things he has found, that a totally albinotic form of the latter, observed in 

 nature, differs from the normally pigmented one only as to one factor: further 

 that the manager of the zoological garden at Hogholmen near Helsingfors Mag. 

 phil. ROLF PALMGREN during the last few years has attempted a few hybridisations 

 between different species and races of mammals and birds and succeeded in arriv* 

 ing at some new and remarkable hybrids. 



Further I beg to add, that papers about the significance of heredity in connect 

 tion with some human diseases and anomalies, are to be found in the transac* 

 tions of the Society of Physicians (Finska Lakaresallskapets Handlingar). 



