( j a N A T M V AXU PHYSIOL Q V F 



the nostrils, and with the assistance of a friend, 1 watched the motions of the soft 

 parts lying within the hollow where the hind legs came out, and 1 found that these 

 motions perfectly corresponded with the motions of the valve, which was put into 

 motion by the expirations and inspirations of the animal. In this manner 1 con- 

 ceive respiration to be carried on in the tortoise, without, however, meaning to 

 extend this explanation to the whole of the genus Testudo, some families of which 

 I have never yet had an opportunity to examine. These animals will therefore 

 materially differ from those of the two preceding families in the mode of respiring ; 

 the air in them being driven into the lungs by the muscles of the throat, which act 

 like a pair of bellows, whilst in these it is performed by the lungs following the 

 motions of their containing parts, and they will therefore differ from the animals 

 having a thorax chiefly in the form and situation of the parts. Respiration is not, 

 I think, the only office of the muscles which 1 have just described; they are closelj 

 connected to the bladder, and to them, 1 think, this animal is indebted for the 

 power it possesses of sucking in water by the anus, as I mentioned in my last dis- 

 sertation ; but this investigation I must leave to another time. 



It will thus be seen, while this close observer fully realized that respiration in the 

 turtle was not effected by deglutition, but by muscles of expiration and inspiration 

 situated in the hank spaces, yet, failing to recognize the true office of the anterior 

 muscles, his conception of the respiratory process was necessarily imperfect and 

 insufficient, and to this, no doubt, must be ascribed the neglect into which his views 

 have fallen. 



In 1819 appeared the most important contribution to the literature of the subject, 

 the monograph of Lunovicus IIenricus Bojanos, on the Anatomy of the Testudo 

 Europaeae. This work being purely anatomical, we have no means of judging 

 a^ to the author's knowledge of the muscular apparatus concerned in respiration, 

 except by the nomenclature he adopts, and some details of description. The in- 

 spiratory muscle and the posterior belly of the expiratory muscle are grouped 

 as abdominal muscles, and described as the obliquus and transversus-abdominis, 

 while the anterior belly of the expiratory muscles, under the name of diaphrag- 

 maticus, is thus referred to: "A corpore vertebrae dorsi quartae et terthe et a 

 costa tertia oriundus, triplici fasciculo complanato, divergentibus eundo; quorum 

 bini ad marginem internum pulmonis, sui lateris, descendunt eique agglutinantur ; 

 tertius vero supra pulmonis anterius extremum revolutes ad peritoneum (a pulmonum 

 facie inferiore versus cardiam et hepar deflecteus) desinit." It is, no doubt, probable 

 that these names have been determined by supposed homologies of the muscles, and 

 yel we may reasonably conclude that Bojanus had not perceived any relationship 

 between the diaphragmaticus and the transversus abdominis, and did not realize that 

 the broad fibrous membrane extending between them was their common tendon. 

 This conception is essential to the full realization of the respiratory process. 



(J. De Cuvier, bearing in mind the type of batrachian respiration, regards the 

 alternate contraction and dilatation of the throal as movements of deglutition of air, 

 and thinks them a sufficient and the only means by which inspiration is effected. 

 The r\|>id-ic>n of the air from the lungs he refers to the agency of two muscles in 



