TRANSACTIONS OF SECTION D. 909 



the ground was bare, and a fallen pupa (always searched for) would have been 

 easily seen ; the hard caudal extremity was frequently left fixed to the supporting 

 surface ; the diiferent results obtained on fences and on bark, &c., are manifestly in- 

 explicable on this ground, the means of fixation being the same. The act of 

 emergence was obviously a much severer test of our method of suspension than 

 that supplied by the motionless pupa ; and yet in a large proportion of cases the 

 empty pupal shell was found hanging to the support, and thus remained for days, 

 in spite of the fact that its lightness enabled each breath of wind to blow it about. 



In future inquiries we trust that a pupa with a wider colour variation than 

 V. urticce may be available. All attempts to obtain the larva of Vanessa io were 

 unsuccessful, but next year we hope to get it and test the bright green and dark 

 forms which its pupa assumes. Other excellent examples would be the bright 

 green, bone-coloured, and dark forms of the pupae of Fieris napi and P. rapee, 

 which have the further advantage of being available for experiment during the 

 winter. Through the kindness of Mr. F. Merrifield we shall be able to carry on 

 the inquiry with these latter and some other species during the winter of 1898-9, 

 when we hope again to appeal to the kindness of the President and Fellows of 

 Magdalen College for the opportunity of continuing the investigation begun during 

 the past summer in the College grounds. 



We also desire to acknowledge the kind assistance we have received from Miss 

 Drummond and Miss Sidgwick in taking notes of the Oxford pupae during our 

 absence in Switzerland, and from Miss Notley for much kind help in the Isle of 

 Wight. Professor H. F. Osborn, Professor F. 0. Bower, and Mr. Arthur J. 

 Evans also witnessed the experiments in the Isle of Wight, and ofiered valuable 

 suggestions and criticisms. 



The investigation, of which this is a brief epitome, was manifestlj' a preliminary 

 inquiry : it has nevertheless yielded far more definite results than we ventured to 

 hope for when we undertook it. 



2. Animal Intelligence as an Experimental Study. 

 By Professor C. Lloyd Morgan. 



It was urged that intelligence in animals is an important factor iu zoological 

 evolution ; that the day of collected anecdotes had passed ; and that experimental 

 work was much needed. Mr. Thorndike's recent experiments on cats were de- 

 scribed, and both the apparatus employed and the curves expressing some of his 

 results were illustrated on the screen. The experiments supported the contention 

 that the method of animal intelligence was that of trial and error, the profiting by 

 chance success. Mr. Thorndike's method was criticised in a friendly spirit ; and 

 recent observations on a fox terrier leading to similar conclusions were briefly 

 described. It was urged that the experimental method gave better opportunities 

 of exact record and a clearer insight into the nature of the association process 

 involved than merely casual observation could possibly do. 



I 



3. On the Families of Sauropodous Dinosauria. By Professor O. C. Marsh. 



The sub-class Dinosauria as known to-day the author divided into three 

 orders : the Theropoda, or carnivorous forms ; the Sauropoda, or herbivorous 

 quadrupedal forms ; and the Predentata, also herbivorous, and including several 

 sub-orders — viz., the Stegosauria and Ceratopsia, both quadrupedal, and the 

 Ornithopoda, containing bipedal bird-like reptiles.' 



The principal characters of the order Sauropoda here discussed may be briefly 

 stated as follows : — 



' The Dinosaurs of North America, Sixteenth Annual Report U.S. Geological 

 Survey. 84 plates. Washington, 189G. 



