684 db. h. charlton bastian on the anatomy and physiology 



organs of circulation.— water-va8culae system, 

 " latera'l and median lines." 



Von SiEBOLD was the first to describe* an excretory system in the Nematoids having 

 a mid-ventral opening in the anterior part of the body. In his ' Manuel * he speaks of 

 this discovery thus : — " Chez plusieurs Nematodes, on observe, h la face ventrale et k une 

 plus ou moins grande distance de I'extremite cephalique, une petite fente transversale 

 entouree d'un sphincter. Chez quelques especes, il en part deux canaux intestinaux, et 

 qui, chez d'autres, sont accompagnes de deux autres canaux qui se portent en avant. Les 

 usages de la matiere incolore et homogene secretee par ces organes ne sont pas encore 

 connus " (p. 140). Since the date of Siebold's first observation, no great accession to our 

 knovi'ledge concerning these structures has been hitherto made, and the opening in the 



to work for about two hours in spite of these symptoms, a general feeling of lassitude and weariness was produced, 

 sometimes amounting to an actual sense of prostration, which would, however, all pass off on desisting from the 

 work and lying down for a few hours. After a few weeks another symptom was superadded, in the form of an 

 asthmatic difficulty of breathing, owing apparently to a constriction of the trachea and of the larger bronchial 

 tubes, which was first noticed about one o'clock one night shortly after going to bed. Without any warning I felt 

 a kind of constriction of the upper air-passages with great difficulty of breathing, each inspiration and expiration 

 being accompanied by an almost musical wheezing sound. This lasted for about three quarters of an hour, when 

 there came a gradual relaxation of the spasm, and all was well again. Such attacks as these gradually became 

 more frequent, generally occurring in the night or evening, lasting longer and often associated with a spasmodic 

 cough, so that much against my inclination I was at last compelled to abstain &om any further examination of 

 these noxious individuals. My system at length became so sensitive to the emanations of this animal that I was 

 even unable to wear a coat which I had generally worn during these investigations, without continually sneezing 

 and suffering from other catarrhal symptoms. Avoiding this and other sources of irritation, after a period of 

 about two months every vestige of these symptoms had disappeared, and continued absent tiU May 1864. 

 During this interval I had never looked at a specimen of A. megalocephala, neither did I once experience any 

 of the old asthmatic difficulty of breathing. For one day in the beginning of May I did work with this animal 

 again ; not so much sneezing and actual irritation was produced at the time, and I was full of hope, but in the 

 evening came one of the old asthmatic attacks, and the influence produced by this one da3''8 work did not com- 

 pletely exhaust itself till the middle of June— a period of nearly six weeks. During all this intervening time I 

 had been subject to occasional spasms and difficulty of breathing. Subsequent isolated periods of work with 

 this Nematoid have also shown me that it takes from one month to six weeks for its effects entirely to disappear. 

 In the spring of this year I again worked daily with these animals for nearly a month, till the symptoms became 

 so severe as absolutely to compel me to desist. A certain change had come over their influence upon me. I 

 now suffered far less from the more local irritating effects, and much more from the severity of the asthma and 

 spasmodic cough. There was a curious kind of periodicity too about the worst attacks ; they generally occurred 

 between five and six o'clock in the morning, and so regularly was this the case that it was almost needless for 

 me to look at my watch, on awaking, to ascertain the hour. These attacks would sometimes last for more than 

 two hours, accompanied by extreme dyspnoea and the most distressing paroxysms of cough. Then at last came 

 a gradual relaxation of the spasm, accompanied by a secretion of thin mucus from the bronchial tubes, followed 

 by an absence of cough and natural breathing for twelve or even twenty-four hours. Not having anatomized 

 these animals since, I have again been entirely free from such symptoms for nearly two months. No effects of 

 this kind were produced by working with A. lumbricoides ; neither does A. megalocephala appear to have 

 affected Dr. Schnetdeb or other anatomists in the manner I have just been stating. 

 * In a Dissert, by Basse, ' De Evolut. Strong. Auric, et Ascar. acuminat.' 1841, p. 13. 



