732 Proceedings of Royal Society of Edinburgh. 
Ewart for a series of papers published partly in the Proceedings of 
the Society and partly elsewhere. In these papers Professor 
Ewart has recorded an elaborate series of experiments designed to 
investigate several questions of great importance bearing on the 
theory of heredity. More especially, he has inquired into the 
subject of Telegony, and as the result of his experiments in crossing 
several mares with a male zebra, and subsequently with a sire of 
their own stock, he considers that strong evidence is given against 
the theory of infection by a previous sire, which has been so 
strongly believed in by breeders of stock. He considers that the 
character observed in the offspring can be more satisfactorily ex- 
plained by the simpler doctrine of Reversion or Atavism. Although 
reversion does not invariably occur, even when extreme forms are 
crossed, it is the usual result of intercrossing and hybrid breeding. 
His experiments also show that intercrossing leads to variation, and 
thus gives species a chance of adapting themselves to changes in 
the environment. He attaches great importance to the influence 
of prepotency, so that a distinct variety may not only hand on its 
own characteristics, but also absorb the chief points of the variety 
with which it is mated. In the course of these experiments he has 
obtained a number of horse embryos at various stages of develop- 
ment, and has in consequence been able to work out many interest- 
ing facts in the life-history of this animal. 
The following Communications were read : — 
1. On Magnetism and Molecular Rotation. By the President. 
pp. 631-635. 
2. On a Bathymetrical Survey of the Scottish Fresh- water Lochs. By 
Sir John Murray and Mr F. P. Pullar, F.R.G.S. 
3. A New Osteometric Board (with Exhibition). By Dr Hepburn. 
