306 DR. T. S. COBBOLD ON SCLEROSTOMA SifNGAMUS. 



particularly, in the hope of direcliug general attention to the 

 mode of checking its ravages, I have ventured to make it the sub- 

 ject of a special communication, which will not, I trust, be the less 

 opportune, following, as it does, Mr. Lubbock's interesting account 

 of Splicerularia* . 



The specimens forming the subject of my recent examinations 

 came into my possession last July, whUst on a visit to my friend, 

 Mr. William J. Fraser, at the Eookery, near Dartford, in Kent. 

 Here my attention was directed to a small, diseased, almost feather- 

 less chicken, which I at once recognized as suffering from the 

 gapes. The bird belonged to a brood consisting of eleven indivi- 

 duals, all of which were between six and seven weeks old. The 

 ten healthy birds had individually attained a considerable size, an 

 average example weighing 9^ ouuces ; but the infested chicken 

 had only acquired a weight of 4 ounces, in consequence of the 

 deteriorating influences of an impeded respiration. Several other 

 equally striking evidences of an imperfect nutrition were obser- 

 vable : among these were the extremely rudimental condition of the 

 wattles, the small body as contrasted with the relatively much 

 more highly developed extremities, and the very scanty growth 

 of the feathers, which on several parts of the body were entirely 

 wanting ; the healthy birds being well fledged throughout. The 

 strange habits of the chicken were also in keeping with its physi- 

 cal peculiarities. It held itself entirely aloof from the other mem- 

 bers of the brood, and, as if to make up for its defective assimilating 

 powers, tried to add to its substance by greedily devouring every 

 thing which came in its way, thus consuming fully two or three 

 times as much as any other member of the brood. The only in- 

 terruption to its constant eating during the day arose from the 

 act of gaping, which took place at irregular intervals, sometimes 

 as often as once every minute. The extension of the neck, and 

 consequent elongation of the trachea, seems to have the effect of 

 separating or unfolding the knot of enclosed parasites- — sufiiciently, 

 at least, to allow of a certain degree of expiration and inspiration. 



Having, on scientific grounds, stated my desire to experiment 

 upon and cure this bird of its disease, Mr. Praser persuaded me to 

 take it away, which I did a few days afterwards, and operated 

 upon it in the following manner : — A very small portion of carded 

 wool having been dipped in chloroform and placed in front of the 

 bird's nostrils, it was soon rendered perfectly iusensible. The 

 skin ofthe neck was then divided and the trachea slit up to the ex- 

 * See 'Nat. Hist. Review,' new series, vol. i. p. 44, et seq. 



