372 proceedings: biological society 



Some of the interesting systematic observations are: the non- 

 trustworthiness of the temporal scutellation and coloration in the 

 Elaphe group; the need of further study in the Tropidonotus fasciatus 

 assemblage; the presence of the Osceola elapsoidea and the Lampro- 

 peltis doliatus coccineus characters in one and the same specimen; 

 the reduction of Diadophis amahilis stidogenys to D. punctatus: the 

 non-recognition of Opkisaurus ventralis compressus; the presence of 

 white-bellied adults and young of Farancia; the possibility of Heterodun 

 niger as an end phase of coloration and a query as to the loss of the 

 azygous in Heterodon hrowni; the overlapping in scale rows and ocular 

 formulae in Storeria occipitomacidata and S. dekayi; the fact that no 

 two heads of the Sceloporus undulatus specimens had the same plate 

 arrangements; and the unreliability of the mental characters in Plestio- 

 don, our specimens of P. quinqiielineatvs falling into two of Cope's 

 major groups, if determined on mental scutellation. {Author^ s abstract.) 



Dr. Wright's paper was illustrated by lantern slides showing views 

 of the swamp, of its reptile inhabitants, and of the variations found in 

 certain of the species. His communication was discussed by the Chair 

 and by Messrs. Wm. Palmer and Hugh Smith. 



The second and last paper of the program was by Dr. Arthur A, 

 Allen, of Cornell University, The birds of a cat-tail 7narsh. 



Observations on the food, nesting habits, and structure of marsh 

 birds showing the limitations of specialized species as to food, distri- 

 bution, and power of adaptability and the dominance of generalized 

 forms were made. 



Specialization in birds goes hand in hand with a high develoj^ment 

 of the instincts but with a low degree of intelligence and little adapt- 

 ability. Generalization of structure on the other hand, occurs with a 

 weaker development of the instincts, greater intelligence, and greater 

 adaptability. The generalized, adaptable species persist through the 

 ages while the specialized, non-adaptable are first to go. This is seen 

 in the birds of a cat-tail marsh. 



Seven stages are recognized in the formation of a marsh, represented 

 in the inature marsh by zones of typical vegetation or plant associations, 

 these associations following one another in regular succession. Similar 

 associations and succession can be recognized among the birds, if we 

 group them according to their nesting range in the marsh. Most 

 species are not confined to one association, although reaching their 

 maximum of abundance in it. The generalized, adaptable species 

 have the widest range. 



The various associations with their typical birds follow: 



I. The Open-water Association: important in suppljdng forage 

 but with no nesting birds. 



II. The Shoreline Association, with the pied-billed grebe, a special- 

 ized non-aclaptable species. 



III. The Cat-tail Association, with the least bittern, coot, Florida 

 gallinule, Virginia rail, sora rail, and red-winged blackbird finding 

 optimum conditions. 



