158 BIOLOGICAL LECTURES. 



logue of Scientific Serials of all Countries, including the Trans- 

 actions of Learned Societies in the Natural, Physical, and 

 Mathematical Sciences, 1633-1876, published by the Library of 

 Harvard University in 1879. 



II. Incidental Bibliographies, or lists of authorities given in 

 special works. As you know, every important article gives 

 more or less extensive references to the previous literature, 

 and one does not need long experience to appreciate the 

 immense advantage of this custom. Especially to the great 

 monographs do we turn for such references, and I may direct 

 your attention especially to the splendid series known as the 

 Fauna and Flora of the Gulf of Naples, which is in our library. 

 The more important text-books usually give carefully selected 

 lists of the more important papers. You will find such in 

 McMurrich's Invertebrate Morphology, Wiedersheim's or Gegen- 

 baur's Comparative Anatomy, Hertwig's Embryology, Korschelt 

 and Heider's Embryology of Invertebrates, and other similar 

 hand-books. But among all works of this class there stand 

 two which are preeminently valuable for their helpfulness in 

 guiding us to morphological and zoological literature ; one is 

 Milne-Edwards' Physiologie, in fourteen volumes (G. Masson, 

 Paris, 1857-1881). This great work is a rich treasury of 

 references, especially to the older literature, which it is some- 

 what the fashion to overlook, although it often contains things 

 which have been forgotten, and which you would do well to 

 make the acquaintance of, if only to learn that the broad 

 foundations of our science were all laid before any of us were 

 born. Milne-Edwards was thoroughly versed in the zoological 

 literature of his time, with, however, a curiously abrupt limit 

 at about 1858. In fact, though his work contains a very large 

 number of references to papers later than 1858, the proportion 

 of omissions is strikingly larger than for papers issued before 

 that date. You will find the consultation of these early 

 authorities especially valuable for anatomical information con- 

 cerning all classes of animals. The present generation is so 

 devoted to comparative morphology and general principles that 

 real anatomical knowledge of animals has become almost a 

 rarity. Thus I find young men who can discuss glibly the 



