Januaex 22, 1909] 



8CIENCB 



159 



pattern and conspicuous surface of the form (B. 

 trthemis) which has been influenced supports 

 strongly the Muellerian hypothesis. The mimic 

 has in fact exchanged its original conspicuous 

 pattern similar to that of the invading Danaine. 



Danaida berenioe of Florida is probably a later 

 invader than plexippus and has modified into re- 

 semblance with itself the mimic already formed 

 under the influence of this last-named Danaine. 

 But the change is so recent that distant traces 

 of the original mimicry of plexippus are easily 

 seen in the floridensis (= eros) form of archippus. 



Evidence in favor of the Muellerian hypothesis 

 is also to be found in the complex group of 

 mimetic butterflies which are ranged round the 

 North American Papilio {Pharmaoophagus) phi- 

 lenor. The female of Papilio asterius, a female 

 form of P. glauous {^turnus), and both male 

 and female of P. troilus form primary mimics of 

 philenor, but also appear to exhibit an evident 

 secondary approach towards one another. Basil- 

 archia (Limenitis) astyanaw, considered by Haase 

 as a mimic of philenor, is rather to be interpreted 

 as a secondary mimic of the three mimetic swal- 

 low-tails. The female of Argymnis (Semnopsyehe) 

 diana, also thought by Haase to be a mimic of 

 philenor, certainly resembles B. (L.) astyanaw, as 

 was clearly stated by Seudder. It is therefore a 

 tertiary mimic. These complex resemblances to 

 mimics and even to mimics of mimics rather than 

 to the central model, are intelligible on the hy- 

 pothesis of Fritz Mueller and not on that of H. W. 

 Bates. 



The concluding section of the address dealt with 

 recent additions to our knowledge of the complex 

 phenomena of mimicry in the females of the Af- 

 rican Papilio dardanus (=:merope), and with 

 seasonal changes in African Njrmphaline butter- 

 flies. A representation of a family of 28 indi- 

 viduals bred from the eggs laid by a hippocoon 

 female of the South African P. dardarms cenea 

 was thrown upon the screen. The family con- 

 sisted of 14 non-mimetic males, 3 hippocoon fe- 

 males, like the parent, mimicking the Danaine 

 Amauris niamius dominicanus; 3 trophonius fe- 

 males, mimicking Danaida chrysippus ; and 8 cenea 

 females, in part mimicking Amauris albimaculata 

 and in part Amauris echeria. The recently de- 

 scribed fiammoides female form of the tropical 

 subspecies of dardanus, extending from Nairobi 

 westward to the Atlantic, was also represented. 

 This is the only form which resembles a model 

 other than a Danaine — ^the Acrasine Pla/ncina 

 foggm. The evolution of the mimetic forms of 

 dardanus from a non-mimetic female like that 



of the Abyssinian P. antinorii or the Madagascar 

 P. meriones was shown to be readily intelligible 

 through the intermediate form trimeni from the 

 Kitnya escarpment. 



In addition to the seasonal forms of the African 

 species of Precis — sesamus, antilope, actia, arch- 

 esia and artaxia, the recent evidence that similar 

 changes may occur in the genus Oharaaes was 

 described and illustrated on the screen. A family 

 of individuals bred from eggs laid by Oharawes 

 neanthes contained one specimen of 0. zoolvrva. 

 This fact conflrmed and placed beyond controversy 

 the evidence that had long been accumulating that 

 these are but forms of a single species. 



This interesting and conclusive evidence has 

 been obtained at Durban, Natal, by Mr. G. F. 

 Leigh, who also bred the large family of P. dar- 

 danus, already referred to. The conclusions as 

 to the seasonal forms of Precis are founded on the 

 specimens bred by Mr. Guy A. K. Marshall at 

 Salisbury, Mashonaland. 



J. S. DrLUEE, 



THE BOTANrCAI SOCIKTT OF WASHINGTON 



The 50th regular meeting of the society was 

 held on November 21, 1908, Vice-president Thos. 

 H. Kearney presiding. The following papers were 

 read: 

 Plant Breeding in England and Sweden: Dr. 



Albeet Mann. 



Dr. Mann's paper, which was illustrated by a 

 number of excellent lantern slides, treated chiefly 

 of the methods of culture of barley, as observed 

 by him during a recent trip to England and 

 Sweden. In England he visited Mr. Beaven, of 

 Warminster; Professor Biffen, of Cambridge, and 

 John Garton, of Warrington. His observations 

 showed that English barley culture is carried to 

 much higher perfection than in the United States; 

 that two-row barley, except in yield, is generally 

 preferred; and that pedigree stock is the only 

 source of permanent grain improvement. At 

 Svalof, Sweden, an ingenious system of classifica- 

 tion and original methods of breeding have pro- 

 duced remarkable results. The two chief ideas of 

 Svalof, namely, the securing of new varieties by 

 selection from old land races and the production 

 of pure pedigree stock by growing such from a 

 single mother plant were fully discussed and in 

 general heartily commended. Information of 

 minor importance was secured from Professor de 

 Vries, of Amsterdam; Professor Johannsen, of 

 Copenhagen; Professor von Tschermak, of Vienna, 



