191 2.] Summary of Agricultural Experiments. 86 i 



The authors have succeeded in proving that this oxidation is mainly 

 due to the presence of tar products in the bath, and that wood tar 

 (e.g., Stockholm tar) in particular favours rapid oxidation. 



This result, it is suggested, points to the need of periodic official 

 analysis in all countries where dipping of cattle is enforced by law. 



Tuberculosis in Cattle (Census and Statistics Monthly, October, 

 191 1). — Practical open-air experiments, which lasted from December, 

 1905, to February, 1909, were carried out under the direction of the 

 Veterinary Director-General of the Canadian Department of Agricul- 

 ture. The objects of the experiments were three : first, to ascertain 

 the effect of open-air treatment on the diseased cattle themselves ; 

 secondly, to ascertain to what extent healthy cattle kept in contact with 

 diseased cattle under open-air conditions were subject to infection ; and, 

 thirdly, to ascertain what percentage of healthy calves it was possible 

 to rear from diseased cows kept without any precautions under open- 

 air conditions. The original herd under experiment at Ottawa con- 

 sisted of 43 animals, but some were slaughtered and additions were 

 made, which, it is admitted, rather detracted from the value of the 

 experiments. Altogether 52 calves entered into the experiments, and 

 of these 29 escaped infection, 21 contracted tuberculosis, and two cases 

 were doubtful. Approximately the proportions were 60 per cent, 

 healthy and 40 per cent, diseased. The proportion of healthy calves, 

 viz., 60 per cent., is at first sight, according to Dr. Rutherford, some- 

 what discouraging ; but when it is remembered that with one exception 

 all the cows on which they were reared were affected with tuberculosis, 

 that one had a tuberculous udder, and that a number of others 

 were open and clinical cases, the matter assumes a somewhat different 

 aspect. It is highly improbable, he thinks, that such a large per- 

 centage of healthy calves could have been obtained from a herd of 

 the same kind under ordinary stable conditions. He states further 

 that the data obtained indicate that open-air life is highly beneficial 

 to tuberculous cattle, and that the danger of transmission to adult 

 cattle kept in contact under these conditions is relatively slight, whilst, 

 on the other hand, the percentage of healthy calves raised by the 

 diseased cows is, as was to be expected, relatively small. 



Horticulture. 



Pollination of Apples (Jour. Roy. Hort. Soc, December, 191 1). — It 

 being accepted that many varieties of apples require pollen from 

 flowers of another variety in order to produce fruit, it becomes of 

 importance to know the time of flowering of different varieties, since 

 the chances of successful pollination will be greater if varieties flower- 

 ing at the same time are intermixed. 



This article gives the results of observations taken at the Royal 

 Horticultural Society's Garden at Wisley as to the average order of 

 flowering of varieties of apples in the four years 1908-11. The 

 earliest date of full bloom of the earliest variety (Red Astrachan) at 

 Wisley was April 21st., and the latest date of full bloom of the 

 latest variety (Royal Jubilee) was May 23rd, and the period of full 

 bloom varied from 18 to 35 days. The dates of flowering of a few 

 of the varieties may be given for purposes of comparison. The number 



