270 Scientific Intelligence. 



has been widely applied as a mode of research only since the 

 opening of the twentieth century and the light which it is throwing 

 on the continental histories since the close of the Paleozoic has 

 come too late to be incorporated into the body of this work. It 

 is to be hoped that an English translation of this, as of the pre- 

 vious volumes, will soon appear in order that a wider and more 

 intimate acquaintance of it among English readers may be 

 acquired. j. b. 



9. Beitrage zur Flora der unteren Kreide Quedlinburgs, Teil 

 II • Die Gattung N~athorstiana JP. Richter and Cylindrites spon- 

 gioides Goeppert ; by P. B. Richter. Pp. 11, with 62 figures 

 and 6 plates. Leipzig, 1909 (Wilhelm Engelmann). — In this part 

 are described in detail two new species of the new Lycopod 

 genus Nathorstiana and Cylindrites spongioides. The latter is- 

 thought to be a strand plant, either a conifer or Pseudocycas. 



c. s. 



10. Cave Vertebrates of America : A Study in Degenerative 

 Evolution ; by Carl B. Eigenmann. Pp. ix, 241, with 72 text 

 figs., 29 plates and frontispiece. Carnegie Institution of Wash- 

 ington, Publication No. 104, July 9, 1909. — Dr. Eigenmann has 

 enjoyed unusual privileges for the study of cave life and its de- 

 generating influence, and the results of his years of study are 

 embodied in this handsome quarto. Some of the more striking of 

 the author's conclusions are as follows : 



" The bleached condition of animals living in the dark, an indi- 

 vidual environmental ^adaptation, is transmissible and finally 

 becomes hereditarily fixed. 



" Ornamental secondary sexual characters not being found in 

 blind fishes are, when present, probably due to visual selection. 



" Individual degeneration of the eye may begin in even earlier 

 stages of development until nearly the entire development be- 

 comes affected, that is, functional adaptations are transmissible." 



The cave environment is divided into three regions : (1) Twi- 

 light just within the cave bounded by the distance to which light 

 penetrates from without; (2) Region of fluctuating tempera- 

 tures ; (3) Inner cave region with absolute darkness, very slight 

 temperature changes. The animals constituting the cave fauna 

 are not all of one class, nor do those within one class belong to 

 one family. They are very diverse in character and origin, but 

 not all families of vertebrates are represented, as a certain predis- 

 position in habit and structure is necessary. 



Caves are populated by one of the four following processes : 

 (1) By accidental carrying into caves; (2) Animals may step by 

 step have colonized the caves, becoming adapted to the environ- 

 ment as successive generations gradually entered deeper and 

 deeper recesses of the caves; (3) Animals which had elsewhere 

 become adjusted to do without light may have gathered volunta- 

 rily in caves; (4) Animals may have developed along with the 

 development of the caves. 



The plant food of cave dwellers is from the nature of things 



