Oct. IS, 1874J 



NATURE 



487 



cultivated ground, old kraals, or cleared forest. On all 

 these spots vast numbers of weeds — many introduced 

 plants — spring up, and appear to be particularly attractive 

 to these insects. These migrations take place as often 

 against as with the wind. 



Papilio mcropc, riiilogroma i>arijncs, Pieris ryiphia, 

 Pieris zochalia, and Tcrias raliel appear to migrate in the 

 direction of the wind, and there are one or two others 

 which perhaps do so also, such as Junonia pclasgis. 

 When resident at Bedford I never saw these butterflies 

 in seasons of drought, but so soon as the southerly winds 

 with rain became abundant a few stragglers might be 

 met with. 



P. gidica, mcsentina, and sc7'erina likewise share in 

 these southerly and northerly migrations. 



Lastly, there are the sudden and almost inexplicable 

 appearance and disappearance of certain species, such as 

 Callidryas rkadia, Diadci>ia misippiis, &c., although I 

 see Mr. Bowker mentions having seen vast swarms of the 

 former in the Drakensberg taking a south-easterly course. 

 During the last two years I have hardly seen a specimen 

 of these two butterflies. The year before they were most 

 abundant. I would here remark that 1 do not remember 

 to have noticed in any entomological work, although the 

 shapes of butterfly wings are accurately described, an 

 account of their peculiar and finely graduated modes of 

 flight. 



Thus, in Pierid.-e, P. heUica flies generally in open 

 ground from flower to flower, but alternately rises and 

 falls and shifts from side to side. Tciias rahel has a 

 similar flight, but slightly more direct ; Coliiis clectra a 

 similar flight, but I think a trifle swifter. 



Cypseliis cajft-r, which preys on these, generally de- 

 scribes semicircles, flying backwards and forwards over 

 the grass in the manner of a scythe working, and it is 

 curious to see how artfully these butterflies, by a slightly 

 higher or lower flight, escape their much swifter winged 

 enemy. 



The different varieties of P. agai/tiiia in like manner 

 vary. The whiter specimens (^5 ) frequent more the open, 

 and are a trifle swifter in their flight than the gamboge 

 and ochreous varieties, or their $. The latter frequent 

 wooded spots, and rise and fall through the foliage like 

 dead leaves, and it is surprising to see how with sluggish 

 movements a slight change of direction saves their lives. 

 P. gidica, i}ies€)iti)ia, severina, and zochalia in like 

 manner vary among themselves in their varieties and in 

 different localities. 



I was particularly struck, when on a visit to Cradock 

 in 1867, by the difl'erence of size and colour and flight in 

 Mesentinas in the Karoo from that of those in the Bedford 

 Forest. 



Papilio coiea, which my observations confirm as being 

 the female of incropc, as so admirably indicated by Mr. 

 Trimen, changes its flight in a remarkable manner when 

 quitting the forest for the open plain. In the forest its 

 flight is remarkably weak, especially if contrasted with 

 that of its mate ; whereas over open plains it rapidly rises 

 out of sight, and soars away like some bird of prey with 

 scarce a flutter of the wing. 



Junonia pdasi^is, archesia, and amatris are in like 

 manner very similar in their flight, but differ with the 

 difference of the localities they frequent ; J. anhesia 

 being intermediate between the forest-frequenting J. 

 pelas^^is and the plain-loving J. amistris. It is also remark- 

 able that where J. archesia frequents the same spots as 

 J. pclasgis, its markings approach that species ; where it 

 delights in open country, about Katfraria, it is bluer, and 

 slightly more like J. amcstris. 



Plymphalis xip/iarcs.—Tht ? of this species is much 

 weaker in its flight than the male, and its coloration, as 

 is known, differs remarkably. Last year I captured it in 

 company with P. merope and 9 P. cchcrioiaes, and was 

 much struck at the time by the similarity of colour and 



pattern, although its imitation is much coarser than that 

 of the other two butterflies. 



A long series of $ and 9 Miyopcs shows a remarkable 

 variation, hardly two specimens being alike, and in one $ 

 a small oblong black spot closes the discoidal cell of the 

 fore-wing. 



On some occasions plants of different orders seem 

 suddenly to increase and then almost disappear for a 

 season or so. This is notably the case with some 

 Composita;. 



As I mentioned in a letter to Mr. Darwin, two species 

 of Graminea;, Tragus alicna and Briza geniciila/a, appear 

 to spring up in the course of locust swarms. I at first 

 ■was rather sceptical on this subject, but by carefully 

 watching the locusts and exa-vamm^ sour veld, where these 

 grasses do not generally grow, I believe that the opinion 

 of the farmer who first called my attention to it is 

 correct. 



Mr. Darwin, I believe, raised plants from locust dung 

 which I sent him, but I am not aware to what species 

 they belonged.* 



JEFFRIES IVVAfAN, M.D. 

 TN the death, on the 4th ulf., at Bethlehem, N.H., of 

 ^ Prof Jeffries Wyman, American biological science 

 has lost one of its most able comparative anatomists. 

 Prof Wyman was born on Aug. 11, 1814, at Chelmsford, 

 Massachusetts, and had therefore just completed his 

 sixtieth year. His father was a well-known physician. 

 He graduated in Arts at Harvard University in 1833, 

 whereupon he commenced his medical education, and 

 took his degree in 1S37, after which he for two years con- 

 tinued his studies in Paris. Returning to Boston he 

 became for some time curator of the Lowell Institute, 

 where he commenced his career as a teaclier by deliver- 

 ing two courses of lectures on comparative anatomy and 

 physiology, in which he first gave indications of the lucid 

 and well-ordered expository powers which throughout his 

 life made him so great a favourite with all liard-working 

 students. In 1844 he became Professor of Anatomy and 

 Physiology in the Medical School of Richmond, Virginia, 

 in connection with the HamdenSidney College. In 1847 

 he succeeded Dr. Warren as Professor of Anatomy in 

 Harvard University ; at which time, from the materials 

 brought from Africa by Dr. Savage, he had the earliest 

 opportunity of describing that naturalist's new genus of 

 anthropoid apes, the Gorilla ( Troglodytes gorilla, Savage). 

 This professorship he held tfll 1866, and it is to him that 

 Cambridge, Mass., almost entirely owes the development 

 of its excellent Museum of Comparative Anatomy. 



Prof Wyman had for many years been a sufferer from 

 phthisis, which necessitated his removing to the warmer 

 cUmate of Florida during the winter months, and the 

 cessation of his lectures and practical work. When the 

 Peabody Museum of American Archaeology and Ethno- 

 logy was established, the founder appointed Prof Wyman 

 one of his trustees, and the board committed the incipient 

 museum to his charge and direction. The seventh annual 

 report of this institution, just issued, was his last produc- 

 tion. Most of his written contributions to science are 

 contained in the Journal and Proceedings of the Boston 

 Natural History Society, of which for many years he was 

 the president ; and in the " Smithsonian Contributions to 

 Knowledge." 



Prof Wyman was a man of singular modesty and 

 truthfulness. His bad health was always in the way of 

 his will to work ; and his desire of completely mastering 

 whatever he undertook, together with a certain over- 

 cautiousness, has limited the number of his works. It 

 is not remembered that he ever had a controversy.^ In 

 his death a gap has been caused which it will be difficult 

 to fill. 



• See " Origin of Species,'' Cih cl,, p ;27- 



