212 



NATURE 



{Dec. 29, 1887 



ill the milk. Lactic fermentation cannot take place unless in 

 the presence of free oxygen, and at temperatures ranging from 

 50° to 114° Y. Below and above these limits the process is 

 ^irrested. The butyric fermentation is caused by a bacillus of 

 larger size than that to which lactic fermentation is due, and 

 occurs in milk free from lactic acid and of alkaline reaction. 

 The bacillus of butyric fermentation will withstand a higher 

 degree of heat, and the spores will stand a boiling heat for five 

 minutes very well. Alcoholic fermentation is induced in milk 

 which has already passed through the stage of lactic fermentation 

 by means of a special ferment which has been used from time 

 immemorial in the Caucasus under the name of kephir. By 

 the action of this ferment a preparation similar, if not identical 

 with koumiss is produced. Siitny fermentation gives what is 

 known in Norway as ropy milk, where it is used as an article of 

 <liet. With this fermentation a micro-organism is also associated. 

 Cheese is a product of fermentation from beginning to end. 

 Not only is it a fermentative process by which the curd is separ- 

 ated from the whey, but the processes of ripening also depend 

 upon various micro-organisms. It is generally thought that the 

 ' lifterences between the cheese made in various localities, and 

 which so well evade imitation, are due in a measure at least to 

 the propagation and prevalence of micro-organisms of a sort 

 which may be rare or wanting in other districts ; and that con- 

 sequently it may be easy to make cheese of a particular flavour 

 or character in one district which it will be found impossible to 

 produce in another district. 



The able paper by Major Craigie, on twenty years' changes 

 in our foreign meat supply, is well worth reading. The paper 

 i.; deeply interesting to agriculturists, and deals with the probable 

 sources of animal food for the constantly increasing human 

 family. The enormous increase of population in the United 

 States of America is especially noticed, and the following 

 extract from the Commissioner of Agriculture's (Mr. Colman's) 

 address to the " Cattle Kings " assembled at Chicago is sig- 

 nificant and hopeful for the future of agriculturists : — " In 1880 

 we had 50,000,000 of inhabitants ; in 1905 we should have 

 100,000,000; in 1930, 200,000,000; in 1955, 400,000,000; in 

 [980, less than 100 years hence, 800,000,000 of inhabitants. 

 Where are these teeming millions to live? On what are they to 

 subsist ? Where and how are the cattle to be bred and reared 

 that must be relied upon to furnish beef?" In answer to all of 

 which questions we may be permitted to point out that many 

 disturbing causes may operate to check this uniform future 

 <levelopment of the population of the States. The won- 

 derful results of geometrical progression have often astonished 

 schoolboys ; and as naturalists we also know what ought to 

 happen in the case of insects, or even of mammals, if their actual 

 increase in the least degree corresponded with their natural 

 powers of expansion. Even the human family does not always 

 increase as rapidly as it might. Stress is laid upon the fact that 

 most of the available land for cattle-ranching has already been 

 laid hold of, and that further extension of this industry has for 

 the present received a check from which it is not likely to re- 

 cover. Also the singular diminution in the numbers of sheep 

 throughout the Old World, and the less noticed fact that since 

 1883 the sheep stock of the United States has lost 6,000,000, 

 must bear upon the price of mutton sooner or later. In the 

 United Kingdom, including islands, we had in 1867 iii sheep 

 to every 100 inhabitants ; in 1887 we have 79. In France they 

 had in 1867 80 sheep to every 100 inhabitants, but in 1887 they 

 only have 59. The same story is told in every Europea'i country 

 without exception, and the sheep population of the world would 

 have most disastrously decreased had it not been for the large 

 increase in stocks in the Australasian colonies and the Argentine 

 Republic. 



The experiments upon ensilage are particularly worthy of 

 attention. The process of ensilage has its devotees, who, like 

 Prof Rogers, consider it to be a panacea for agricultural 

 distress. This sanguine view has been supported by the ex- 

 perience of many agriculturists, who have not the least doubt 

 as to the superiority of silage over hay, and who also look upon 

 the peculiar succulence of silage as a fact of great importance. 

 One thing, however, appears certain — that, valuable as ensilage 

 may be, it cannot equal in nutrient properties young growing 

 grass. Hay or silage may be of more value in winter than 

 is grass in summer, but intrinsically grass is that perfect product 

 of unaided Nature which no art can better. 



An optimist view thus stated may be challenged, and the pro- 

 pounder asked if the fresh clusters of the grape are equal to the 



ripened vintage wine ? The matter requires to be dealt with 

 scientifically, and it is with a view to clearing up the matter that 

 the Royal Agricultural Society has with the aid and concurrence 

 of the Duke of Bedford carried out a series of crucial experi- 

 ments upon the value of ensilage as a stock food in comparison 

 with the value of hay. Such an experiment is liable to many 

 sources of error. The Wilmington experiments of 1886 abounded 

 in them. There was no guarantee that the hay as hay was as 

 good as the silage as silage. There was no record as to the com- 

 parative areas of land required to produce the hay or the silage. 

 The large amount of silage eaten by the bullocks bore an un- 

 satisfactory relation to the small quantity of hay eaten, indicating 

 that the ensilage was good and palatable, while the hay was un- 

 palatable. This inference is borne out by the dictum of the 

 Society's chemist, that the hay at Wilmington was "very inferior 

 indeed," while the silage " was really well made." Such sources 

 of error invalidate the results obtained, and if, as was the case, 

 the cattle fed on good silage did better than those fed on bad 

 hay, all we can say is that no other result could very well have 

 been expected. At Woburn the experiments were more strictly 

 conditioned. " 5^ acres of ground were carefully measured out, 

 and the grass was only cut as it was wanted for carting to the 

 silo, not being allowed to lie on the field any length of time. 

 Two carts going side by side were filled simultaneously, and 

 then taken to be weighed. After weighing, one cart went to the 

 silo, into which grass was to be filled, and the other went to a 

 meadow, where the grass was spread and left for haying," I 

 must not take up space by explaining the complete system of 

 sampling the grass, and the two products of hay and silage. 

 Suffice it to say that the utmost pains was taken to obtain 

 thoroughly representative samples for purposes of analysis. 

 The hay and silage thus obtained might be considered as strictly 

 comparable with one another, and if the process of silage is 

 preferable to the older and more fragrant system of hay-making, 

 the comparison might here be instituted with every prospect of 

 deciding the question. The experiment was made upon twelve 

 Hereford steers, six of which were placed on a diet of 3 lbs. 

 of cotton cake, 5 lbs. of maize meal, with hay ad libitum and 

 water ad libitjim. The other six were given 3 lbs. of cotton 

 cake, 5 lbs. of maize meal, with silage ad libitum, and water ad 

 libitum. The conditions were the same except with regard to 

 the hay and the silage. The bullocks were practically of equal 

 size and weight, although the six bullocks which were placed on 

 the ensilage side of the experiment had the advantage of 9 lbs. 

 over the hay-fed lot, and weighed 60 cwt. i qr. 20 lbs. The 

 result after thirty days' feeding was that the hay-fed bullocks 

 had increased more in weight, the comparative merits of the two 

 systems of feeding being as follows : — 



Gain per day per head of bullocks receiving hay . 2*3 lbs. 

 Ditto ditto ditto silage. 2'i lbs. 



During the succeeding month the result was in favour of the 

 ensilage, but in the total period of 84 days, which terminated on 

 March 10, 1887, the result was : — 



Gain of hay-fed bullocks . . I "96 lbs. per day. 

 Ditto silage ditto . . .1-98 lbs. ditto. 



A very curious result was arrived at with reference to the relative 

 amounts of hay and water and of silage and water consumed 

 during this period. The six bullocks receiving hay consumed 

 of hay 20'3 lbs. per head per day, and drank 707 lbs. of water, 

 or a total of hay and water of 91 lbs. each. The six bullocks re- 

 ceiving silage consumed of silage 51 lbs. and of water 40' i lbs., 

 or a total of 91 lbs. each. This very closely accordant result 

 appears to point to the conclusion that the only difference be- 

 tween hay and silage is water, and that hay with plenty of water 

 is quite as good a food for fattening bullocks as silage with less 

 water. 



The progress of the Hessian fly is a topic of considerable 

 public interest, and no one could more satisfactorily enlighten us 

 on the subject than Mr. Charles Whitehead. We are told by 

 this excellent practical entomologist that the Hessian fly appeared 

 first in America in 1779, and that a great scare prevailed in 

 England at that time, which turned out to be unfounded. The 

 nearest country to Us at present affected with the pest is Russia, 

 which appeared to firs't receive this unwelcome visitant in 1879, 

 and it is still a moot point whether our Hessian flies have arrived 

 from America or from Russia. That we have it rather bad is 

 plain from the fact that the insect has been proved present in 

 twenty English counties. The theatre of its operations is likely 



