42 THE INTERNAL PARASITES OF 



each of these being capable of developing in its interior 

 some 30,000 eggs ; consequently, if all the joints of such 

 a worm should arrive at perfection, they would col- 

 lectively afford a total of more than thirty millions of ova. 

 It is not usual, however, to find at one time more than 

 seventy or eighty of the joints full of perfectly ripe eggs. 

 On the other hand, it must be borne in mind that, as 

 during life the ripe segments are cast off at the rate of 

 about 400 per month, any one person who is playing the 

 part of host to this worm is liable to be the means of dis- 

 persing abroad upwards of one hundred millions of these 

 eggs annually. Of course only a very small number of 

 the ova thus distributed ever arrive at their destination 

 within the bodies of cattle ; nevertheless, as we have 

 seen, a sufficient number of them gain access to the 

 intermediary bearers to ensure for the species an exten- 

 sive propagation. Fortunately, as one substantial result 

 of scientific research, we know how to put a limit 

 upon the amount of egg- dispersion, and thus check a 

 nuisance which, without proper precautions, might be- 

 come well-nigh intolerable. 



The subject of egg dispersion in connection with the 

 propagation of parasites in general, and of tapeworms in 

 particular, is too large to be discussed here to the extent 

 which it deserves, especially if we should consider the 

 facts in relation to the sewage question. In its bearings 

 on the public health, this phase of the subject has already 

 been treated of in the pages of the Field for March 1 8, 

 1865. I must, however, further enlarge upon this topic 

 in connection with the production of the bladder-worm 

 disease of cattle. If at home it be the fashion in certain 

 quarters to ignore the facts of the case, it must, at all 

 events, be allowed that the attitude of our Indian 



