ON THE DEVELOPMENT AND MIGRATIONS OF THE ENTOZOA. Ill 



lions, to convert a given number of degrees of Fahrenheit into the corre- 

 sponding degrees of a Reaumur or a Centigrade thermometer. 



Sir William Armstrong remarked, at Newcastle-upon-Tyne, in his address 

 to the British Association in 1863, that our thermometric scale had been 

 originally founded in error : he regarded it as most inconvenient in division, 

 and advised that the Centigrade scale should be recognized by the numerous 

 men of science composing the British Association. 



The distinguished President of the British Association stated his regret 

 that two standards of measure, so nearly alike as the English yard and the 

 French metre, should not be made absolutely identical. We in England, 

 observed Sir William, have no alternative biit to confonn with France, if we 

 desire general Uniformity. He was convinced that the adoption of the deci- 

 mal division of the French scale would be attended with great convenience, 

 both in science and commerce. He could speak, fi-om personal experience, 

 of the superiority of decimal measurement in all cases where acciu'acy is 

 required in mechanical constiiiction. In the Elswick works, as well as in 

 some other large establishmeuts of the same descri^jtion, the inch is adopted 

 as the unit, and aU fractional parts are expressed in decimals. " No diffi- 

 culty has been experienced in habituating the workmen to the use of this 

 method, and it has greatly contributed to the precision of workmanship. 

 The inch, however, is too small a unit, and it would be advantageous to 

 substitute the metre, if general concurrence could be obtained." 



Report of Experiments respecting the Development and Migrations of 

 the Entozoa. By T. Spencer Cobbold, M.D., F.R.S., F.L.S., 

 Lecturer on Comparative Anatomy at the Middlesex Hospital. 

 At the Cambridge Meeting of this Association in 1862, I offered a brief 

 resume of the principal facts then known in relation to the origin and mode 

 of development of the Entozoa Uable to infest the human body ; but, not- 

 withstanding the very interesting discoveries which Contiaen'tal observers 

 had made on this subject, it stiU appeared that there was room for further 

 inquiry. In this view I proposed to institute a series of experiments, partly 

 for the pui'pose of verifying previously recorded statements, but more par- 

 ticularly with the intention of adding to our stock of hehninthological facts. 

 The General Committee, in approval, sanctioned and encouraged this pro- 

 position J and I therefore proceed to explain the nature of the experiments 

 adopted. Though the results arrived at exhibit, for the most part, a nega- 

 tive aspect, yet in some instances the reverse of this is the case, whilst, 

 under any circumstances, the facts are calculated to prove more or less 

 instructive, and all of them tend to advance a department of science in the 

 progress of which our present and future social welfare is deeply concerned. 

 I have not, indeed, limited my inquuics to particular human parasites, 

 but have employed all such helminthic forms as I have been able to procure 

 in a satisfactory condition for experiment. In this couutiy, and especially in 

 London, great difficulties are placed in the way of any one engaged in 

 biological pursuits involving the keeping of dogs and other animals ; and, last 

 year (1863), these obstructions were, I fear, somewhat enhanced by certain 

 misguided individuals who seem to entertain the idea that phj-'siologists 

 delight in the practice of cruelty. The destruction of game by the sports- 

 man, the capture of fish by the hook, and the slaughter of domestic animals 



