292 NATURAL SCIENCE. May, 



the yolk-sack among reptiles. Owen described it in a number of 

 birds, declaring that the retention of a large rudiment was charac- 

 teristic of water-birds. More recently, Mr. Chalmers Mitchell has 

 shown that it is present in the adult forms of the greater number of 

 the avian groups, and that it bears a constant relation to the disposi- 

 tion of the intestinal folds. There are few records of its occurrence 

 among adult quadrupeds ; but human anatomists are familiar with it 

 as a not infrequent abnormality known as Meckel's diverticulum. 



The Evolution of Adaptations. 



We have received from Mr. G. D. Haviland a pamphlet entitled 

 " Some Factors in the Evolution of Adaptations " (London : 

 R. H. Porter, price sixpence). He endeavours to apply deductive 

 reasoning to a set of propositions concerning asexual and sexual 

 reproduction. So far as we can see, there is no flaw in his ingenious 

 exercise ; but as it happens, deductive reasoning is the last thing 

 we want in biology. Everyone of us, though perhaps seldom with 

 Mr. Haviland's skill, might sit down and deduce factors of evolution 

 until the undertaker's man called for us, and science would be none 

 the better for our labour. One of Mr. Haviland's "three axioms," 

 for instance, is that the characters dealt with in- his paper " exhibit 

 heredity of deviation." If the writer were to spend a very small part 

 of the leisure he is able to devote to this pastime of deduction upon 

 the collection of new facts and the collation of old facts regarding the 

 meaning and manner of the process he cheerfully calls an axiom, he 

 might write something worth reading. When the axiom that two 

 straight lines do not enclose a space is stated, a definite fact is stated. 

 This axiom of Mr. Haviland, on the other hand, is a generalisation of 

 the vaguest kind, based upon observations which range from absolute 

 non-inheritance of particular deviations to complete inheritance. We 

 want facts, not inferences, observations, not theories, for a long time 

 to come. 



The Anatomical Society. 



We hear that it is intended to hold a summer meeting of the 

 Anatomical Society of Great Britain and Ireland at Oxford on 

 Saturday, July 4. This Society, which was founded in 1887, meets, 

 as a rule, four times a year, three of the meetings being held at the 

 London medical schools in rotation, and the other at one of the 

 provincial universities or schools. The aims of the Anatomical Society 

 may fairly be said to come within the province of Natural Science, 

 since it is instrumental in publishing a considerable number of papers 

 on vertebrate morphology, as well as on pure anthropotomy. Among 

 the papers which are likely to interest, or to have been of 

 interest, to our own circle of readers, we may refer to the following : 

 The Structure of the ^"ertebrate Liver, by T. W. Shore and Lewis 



