738 THE DISEASES AND DISORDERS OF THE OX. 



lessons to be learned from these conclusions are that the eruptive diseases of 

 cows should be studied with the greatest care, and that all milk should always 

 be boiled before being consumed by human beings. 



In the report just issued, Dr. Klein shows that the sub-cultui'es from human 

 scarlatina, inoculated into cows which have recently calved, can produce in 

 those cows, along with other manifestations of the Hendon disease, the 

 characteristic ulcers on the teats— ulcers seemingly identical with those 

 observed at the Hendon fann. Moreover, the sub-cultures, established either 

 from the human or the cow disease, have the same property of producing in 

 various rodents a disease similar in its pathological manifestations to the Hendon 

 disease of cows and to scarlatina in human beings. Calves fed on sub-cultures 

 established from human scarlatina obtain the Hendon disease ; and children fed 

 on milk from cows suffering from the Hendon disease became affected with 

 scarlatina. It is, therefore, clear that the Hendon disease is a form, occurring 

 in the cow, of that which we call scarlatina when it occurs in human beings. 



In the course of tlie inquirj-, some difficulty was occasioned by the appearance, 

 at a farm in Wiltshire, of an eruptive malady in cows which was at first supposed 

 to be identical with that which had been observed at Hendon, but with which 

 no scarlet fever was associated ; and also by an outbreak of sore-throat at 

 Edinburgh, among the consumers of the milk furnished by a particular dairy. 

 The cows in this dairy had an eruptive disease of the teats and udders ; but the 

 sore-throat Avhich followed the use of their milk could not be recognised as 

 either scarlatinal or diphtheritic ; and, on one of the cows being sent to Dr. 

 Klein, the disease, although inoculable into calves, and presenting affinities with 

 the Hendon disease, was yet found to be clearly distinguishable from the latter 

 by certain differences with regard to the progress of each, by the condition of 

 certain organs after death, and by the inoculability of one or the other into 

 rodents ; differences, in short, which led Dr. Klein to the conclusion that this 

 Edinburgh cow-disease is not the same as cow-scarlatina. With regard to the 

 Wiltshire outbreak, the same observer finds that this also, although attended by 

 a somewhat similar eruption, differs from the Hendon disease in almost every 

 other character, and appears to bear no kind of relation to scarlatina. 



The identification of manj- different maladies accompanied with eruptions in 

 cows may be most hopefully attempted by a study of the forms of bacterial 

 life which are associated with each different disease. 



These bacteria are of the kind called " streptococci," so-named on account 

 of their tendency to miite together in chains ; and Dr. Buchanan points out that 

 there is as little difference, to the less educated judgment, between one and 

 another chain-forming micrococcus as, to the eye of the ordinary dweller in 

 towns, exists between the swift, the swallow, and the martin. Dr. Klein formu- 

 lates seven sets of characters, serving to distinguish between one and another 

 organism of the group. Hence the application of seven tests is required before 

 an assertion of the identity of any two streptococci can, even provisionally, be 

 made. In a special report on the various streptococci. Dr. Klein refers to nine 

 varieties, which do not include all the members of the class which he believes to 

 possess distinguishing characteristics of their own ; and he shows that sonie at 

 least of these differ widely, not only in the characters which he points out, but 

 also in the effects which they produce when introduced into the animal body by 

 inoculation or by swallowing. The minute care which has been bestowed upon 

 these researches is almost beyond praise, and should convey an instructive 

 lesson with regard to the extreme difficulty of conducting them. 



