242 TRANSACTIONS OF THE [JUNE 5 
May 29, 1892. 
Sratep Meerina, 
Pxesipent Borron in the chair, and fifteen persons present. 
Dr, Marcus Brensamin read a paper entitled: ‘‘ The Develop- 
ment of Science in New York City.”’ 
June 5, 1893. 
Recuxiar Business Meretina. 
Presipent Borron in the chair, and five persons present. 
The following papers were read by title: ‘The Chordeumide 
of North America,’’ by O. F. Cook and F, P. Collins. 
NOTE ON THE POSITION OF THE CLOACAL APER- 
TURE IN CERTAIN BATRACHIAN TADPOLES. 
BY ARTHUR WILLEY. 
An interesting feature in connection with the study of Tera- 
tology is concerned with disturbances in the topographical 
relations of parts produced by mechanical means or, in other 
words, by the differential growth of neighboring structures. 
One of the effects of such disturbances introduced secondarily 
into the life-history of an organism, is to give rise to a condition 
of asymmetry in the relations of this or that organ. At its first 
appearance, in whatever form, an asymmetrical condition must be 
regarded as anomalous, and we thus arrive at the paradoxical 
conclusion that an anomaly may, on being fixed and rendered 
constant by inheritance from generation to generation, become 
the normal state of things. This is only another way of saying 
that, ‘“‘La tératogénie est capable de produire des espéces 
nouvelles.’”’ (See Paul Hallez, ‘‘Morphogénie générale et 
affinités des Turbellariés.’’ Lille 1892.) 
While examining recently a number of tadpoles, which were 
identified with the assistance of Mary H. Hinckley’s paper 
“On Some Differences in the Mouth Structure of Tadpoles of 
the Anourous Batrachians found in Milton, Mass.,’’ (Proc. Bost. 
Soc. Nat. Hist. XXI., 1881, pp. 307-314, Pl. V.), as the probable 
