284 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



is on record. Dr. E. L. Sturtevant, on removing (March 15) 

 some eggs from a pickerel, found that some of the eggs 

 "had evidently developed in the line of the fecundated vgg, 

 as the cells were arranged in the form of a curled fish, the 

 line of the back being well defined, the line of the belly and 

 sac poorly or not at all defined, while there was a concentra- 

 tion of cells about the locality of the eye. I cannot say that 

 I saw a young fish, for I did not, but I saw what I consider- 

 ed sufficient to interpret as development to a certain degree 

 without fecundation." The account in full appears in the 

 American Naturalist for August; and in a succeeding num- 

 ber Professor W. K. Brooks gives a history of what is known 

 on this subject. 



VERTEBRATES.* 



Progress in Vertebrate Zoology has been essentially sim- 

 ilar to that in past ordinary years. No discovery of a start- 

 ling character has been made, but the usual activity has 

 been manifested in the search for and description of new 

 species, in the more or less careful elaboration of small 

 groups and faunas, and in anatomical studies of special 

 forms. We here confine ourselves to notices of a few con- 

 tributions which have a general interest, or relate to the 

 Xorth American fauna. 



The Limits of the Branch of Vertebrates and its Classes. 



Until quite recently, and since Cuvier first established the 

 "embranchement" of Vertebrates, the group so designated 

 was accepted without hesitation with the limits originally 

 given to it. Charles Bonaparte, the Prince of Canino, hail, 

 indeed, in 1856, proposed to relegate to the branch the ver- 

 miform Sagitta as the representative of a peculiar class ex- 

 hibiting a retrograde metamorphosis; but the suggestion 

 fell still-born, and no further attention has been paid to it. 

 Lately, however, there has been a disposition to modify the 

 limits of the branch in opposite directions* Semper, for ex- 

 ample, wished to eliminate IhxincJiiostoma (Amphioxus), or 

 the class of Leptocardians, from the group, while others have 

 been disposed to approximate to it the Tunicates, which for 



By Professor Theodore Gill, of Washington, D. C. 



