September 1, 1905.] 



SCIENCE. 



271 



be considered at best as only casual, and the 

 infertility of hybrids, especially among the 



within the bounds of a two-acre tract of land." 



' On the Breeding of Helmintlioplula pinus with 

 H. leucohronchialis at Englewood, New Jersey,' 

 by Frank M. Chapman, American Museum of 

 Natural History, New YorI<: City, AuJx, Vol. IX., 

 No. 3, pp. 302-303, 1892. Record of typical male 

 H. pinus, breeding with non-tj^pical female H. 

 leucoltroncJiialis. Description of nest and eggs. 

 This pair of birds deserted the nest and further 

 observation could not be made. 



' Notes from Connecticut,' by E. H. Eames, 

 Bridgeport, Conn., Ank, Vol. X., No. 1, pp. 89-90, 

 1893. Mr. Eames writes: "« * * while on the 

 other side and within a stone's throw a beauti- 

 ful Brewster's warbler spent the greater part of 

 his time. The latter after patient watching re- 

 vealed his mate, a blue-winged warbler, and a nest 

 in course of construction. * * * When seen 

 again, on June 14, it contained four eggs, two of 

 which were cowbirds', which were removed. 

 Those remaining brought forth a pair of birds 

 that, as they left the nest, could not be distin- 

 guished from normal young of the female parent, 

 as would be expected, whatever the color of the 

 male." 



• HelminthopMla leucobroncMalis,' by Louis B. 

 Bishop, M.D., New Haven, Conn., Auk, Vol. XI., 

 No. 1, pp. 79-80, 1894. "On July 1, 1893, I 

 found an adult H. leucobroncMalis with two 

 young in a small tract of alder swamp and wood- 

 land of North Haven, Conn. They were little 

 disturbed at my presence, and I watched them 

 carefully for some time. The adult fed both 

 young at short intervals, leaving little doubt of 

 its relationship to them. On July 4 they were 

 still in the same locality, and I collected all three. 

 Possibly the remainder of the family had been 

 killed, as a careful search on both days through 

 the adjacent country failed to disclose any other 

 member of the genus HelminthopMla . 



" Decomposition was so far adA'anced before I 

 could prepare the adult that I was unable to de- 

 termine its sex. The fact that it never sang 

 while I was watching it, together with the 

 generally dull color of its plumage, lead me to 

 think it a female. 



" Unfortunately both of the young were still 

 principally in the olive, downy plumage of nest- 

 lings, but enough of the final feathering had ap- 

 peared on the throat, breast and upper parts to 

 make it certain that one, and probable that the 



higher animals, is too well known to need 

 further comment here. If it be conceded 

 then as improbable that over one hundred 

 cases of wild hybridity have occurred between 

 H. chrysoptera and li. pinus, only one other 

 conclusion can be reached, namely, that from 

 one of these warblers (probably H. pinus) 

 there began to occur ' mutations ' that have 

 increased in geometrical progression and have 

 finally grown sufficient in number to become 

 themselves a parent stock, though it seems 

 probable that the ' mutations ' are still occur- 

 ring from the ancestral stock, as witness the 

 observations of good field ornithologists al- 

 luded to above, who say they have seen H. 

 pinus feeding young which they supposed to 

 be H. leucotronchialis. They supposed the 

 young to be H. leucotronchialis, because in 

 every case one of the parents was H. leuco- 

 hronchialis, but, on the other hand, in every 

 case, one of the parents was an H. pinus. 

 Now the cases where such conditions have pre- 

 vailed are five in number. It is significant 

 that while the generally accepted hypothesis 

 to account for the origin of H. leucohronchi- 

 alis, is that H. chrysoptera has crossed with 

 H. pinus, the result being a hybrid, H. leuco- 

 hronchialis, yet in no case has any naturalist 

 asserted that he has seen H. chrysoptera feed- 

 ing young supposed to be H. leucohronchialis. 

 I am aware that there are two cases" of the 



other would have become a typical specimen of 

 H. pimis. The Aving-bars of the young differ, be- 

 ing in the most mature specimen narrow and 

 almost white, and in the other broader and light 

 yellow." 



" ' Evidence concerning the Interbreeding of 

 HelminthopMla chrysoptera and H. pinus,' by A. 

 K. Fisher, M.D., Sing Sing, N. Y. "On July 4, 

 1885, while collecting specimens in a piece of 

 woods underlaid by a scattering undergrowth, I 

 came upon a female golden-winged warbler busily 

 engaged in collecting insects. As I stood watch- 

 ing her she flew to a neighboring cedar tree and 

 commenced to feed a young bird. I immediately 

 shot and killed the latter as the female flew 

 away. The noise of the discharge started an- 

 other young bird from some bushes near by, and 

 as it flew the female flew and alighted near it. 

 Just as I was on the point of firing they started. 



