688 BEPORT— 1886. 



having peripheries not circular but more or less elliptical, would not be likely to 

 rotate. The author has found that flat chips of wood, of even rhomboidal 

 periphery, roU freely on the edge when impelled by sufficient wind along such a 

 surface as the horizontal woodwork of a pier, the difference between the move- 

 ment of such a departure from the circular, and that of a circular periphery, being 

 less visible iu the rotation than in the translation, the latter being of a proportionally 

 interrupted kind. The difference between a rhomboidal and a circular periphery 

 being so much greater than that between a circular and an elliptical, it appears to 

 the author the objection referred to vanishes, viz. that the latter (in the ' Aves ' 

 and ' Camelidse ') would not be likely to have rotation. The author would suggest 

 the possibility that in the ' Aves ' and ' Camelidse ' a less continuous and more inter- 

 rupted impingement of the red disc on the nervous and muscular tissue, for their 

 due stimulation, may be in request. Referring again to the paper in the ' B. A. 

 Report of 1881,' where the author points out that, if there be rotation of red 

 discs it must be wholly suppressed when the capillaries are reached, and then and 

 there appear as heat, he would venture to ask if this supposition does not offer 

 a reasonable view that may account for the missing link in the otherwise accepted 

 theory of animal heat ? The imaccounted portion is alleged to be but small, and 

 such only would probably be the increment from the suppression of the rotation 

 by the capillaries — the locality where the wanting increment has to be looked for. 



SATURDAY, SEPTEMBER 4. 

 The following Reports and Papers were read : — 



1. Beport on the Miyratioti of Birds — See Reports, p, 264. 



2. Beport of the Committee for promoting the Establishment of a Marine 

 Biological Station at Granton. — See Reports, p. 251. 



3. Beport on the Becord of Zoological Literature. 



4. Beport of the Committee for investigating the Mechanism of the Secretion- 

 of Urine. — See Reports, p. 250. 



5. On the Flora of Ceylon. By Dr. Teimen. 



Sub-Section ANIMAL MORPHOLOGY. 



1. On Man's Lost Incisors.^ 

 By Professor Windle, M.A., M.D., and John Humphreys, L.D.S.L 



Teeth beyond the ordinary number may occur in the incisive portion of the 

 dental series. Such teeth may fall into one of two categories — viz., supplemental, 

 that is, incisiform though generally smaller than the ordinary incisors ; and super- 

 numerary, which are conical and do not conform to any human dental type. Similar 

 teeth have been observed in other parts of the dental series also. Eustachius, 



' Published in extenso in the Journal of Anatomy and Physiology, vol. xxi. p. 84. 



