386 Scientific Intelligence. — Zoology. 



two horses each team, upon light sandy soil, = 1561b.; the 

 second result is from seven teams, of two horses each team, upon 

 loamy ground near Great Berkhamstead, = 154 lb. ; the third 

 result is from six teams, of four horses each team, with old Hert- 

 fordshire ploughs, = 127 lb. ; the fourth I'esult is from seven 

 teams, of four horses each team, upon strong stony land (im- 

 proved ploughs), =: 167 lb. ; the fifth result is from seven 

 teams, of four horses each team, upon strong stony land (old 

 Hertfordshire ploughs), = 193 lb. ; the sixth result is from seven 

 teams, of two horses each team, upon light loam, = 177 lb. ; 

 the seventh result is from five teams, of two horses each, upon 

 light sandy land, = 170 lb. ; the eighth result is from seven 

 teams, of two horses each, upon sandy land, = 160 lb. The 

 mean force exerted by each horse from fifty-two teams, or 144 

 horses, = 163 pounds each horse ; and, although the speed was 

 not particularly entered, it could not be less than at the rate of 

 9i\ miles per hour. As these experiments were fairly made, and 

 by horses of the common breed used by farmers, and upon 

 ploughs from various counties, these numbers may be consider- 

 ed as a pretty accurate measure of the force actually exerted by 

 horses at plough, and which they are able to do without injury 

 for many weeks ; — but it should be remembered, that if these 

 horses had been put out of their ustuil walking pace, the result 

 would have been very different. The mean power of the 

 draught horse, deduced from the above mentioned experimentSj 

 exceeds the calculated power from the highest formula of Mr 

 Leslie. — Annals of Philosophy, vol. viii. p. 22. 



24. Fertility of the Unio Pictorum. — Dr Unger, in his inte- 

 resting anatomico-physiological account of this animal, published 

 at Vienna in 1 827, already mentioned, reckoned in a full grown 

 animal 300,000 embryos and young individuals. This extraor- 

 dinary abundance, which does not occur in animals lower in the 

 scale, as in the medusae, appears even considerable when con- 

 trasted with the fecundity of insects. This vast number is pro- 

 bably the production of only a single year, which will give for 

 the whole life of the animal a produce of many millions of indi- 

 viduals. 



25. Traditional Story regarding the last of the Wolves in 

 Morayshire. — The last wolves existing in this district had their 



