INAUGURAL ADDRESS. 173 



A wide field of investigation is open to the patient Natiu'alist who 

 will devote his energies to the study of that strange class of organisms, 

 the parasites of man. Dr. Spencer Cobbold, the most eminent of 

 British Helminthologists, who has recently honoured our local society by 

 accepting the office of honorary ^dee-president, is now engaged in 

 pubhsliing, in the " Midland Naturalist," a series of papers in wliich he 

 brings before our notice the fact, that the complete life-histoiy of many 

 of these human plagues is yet untraced. Here is full and useful occupa- 

 tion for such of you as have the necessaiy patience and application. 

 The full career of some of them has been clearly demonstrated, through 

 a series of metamorphoses more strange and bewildering than any we 

 have read of in the fabulous pages of Eastern tale ; wonderful 

 as are the records of the Thousand-and-One Nights, no story 

 related by Sheherazade is so full of marvel as that of the 

 varying phases of the life-career of a simple cestode worm. 

 In unraveUing the thread of such a career, and distinctly tracing it 

 through all its changes, you may by some happy discovery of the 

 pecuharities of one or other of these formidable guests, gain the proud 

 distinction of having conferred a benefit on mankind. At present we 

 know what fatal mischief they work upon their hosts ; but our know- 

 ledge is not sufficient to enable us to guard effectually against their 

 unwelcome visits. It must be that, in a union of so many desirous of 

 penetrating the secrets of nature, some by education and tastes are 

 eminently qualified for this difficult pursuit. Its utihty ought to be a 

 sufficient inducement to follow it, and the absorbing interest it would 

 generate in its followers would be their sufficient reward. 



This special field of observation is not hmited, as to its objects, to 

 the ordinary entozoa and epizoa, which hitherfo have been included in 

 the Usts of the Hehninthologist ; most of these are distinctly visible 

 without the assistance of the microscope, which is only required for the 

 examination of the details of their structure ; there is evidence of the 

 existence of a large class of organisms, whose interference with our vital 

 economy is far more fatal than that of ordinary parasites ; these are so 

 minute as to tax the skill of the most expert histologists, and require 

 the most perfect instruments to detect their existence. The generally 

 accepted theory of their action appears to explain satisfactorily the 

 course of many fatal diseases, as scarlet and other fevers, measles, small- 

 pox, and, in fact, most of the diseases attributed to contagion ; but much 

 miore evidence is required to estabhsh the theoiy on a firm basis. 

 Already a large body of acute observers throughout the scientific world 

 are engaged in pursuing this study; and the evidence obtained with 

 reference to one particular form of disease — splenic or relapsing fever — 

 appears to be conclusive, as numerous specimens of a pecuhar form of 

 Bacteria, called Spirilla, are alwaj's found to be present in the blood of 

 persons while suffering fi'om this fever, wliich disappear during the 

 intermissions, and when the fever passes away. Other forms of Bacteria 

 have been detected in the blood in other diseases ; but much evidence is 

 still required to distinguish and identify them as the several causes of 

 the mischief in the varying forms of contagion, the search for which will 



