2 \ N A TO MY AND PHYSIOLOGY P 



authorities, we were surprised, on afterwards learning the singularly truthful views 

 of Townson, to find the) had fallen unappreciated, and that, in many instances. 

 t h e y ),;„[ n0 | even been honored l>\ a notice, or, when so noticed, had been men- 

 tioned only to be condemned. 



Physiological Observations on the Amphibia. Dissertation the Thin!, on the 

 Respiration of the Tortoise. Robert Townson. 



The first inspection of the structure of the animals 1 have lately treated of, the 

 Ranse and Salamandrae of Linnaeus, will show that respiration cannot be performed 

 in them as it is in man and animals similar to him; the absence of the osseous parts 

 and diaphragm is sufficient to demonstrate this; and though, on the records of 

 physiology, there are instances of the continuation of respiration after the mobility 

 of the osseous parts had ceased, yet, as these were only instances of suffering nature, 

 where the accompanying assistant, the diaphragm, still continued in full energy, phy- 

 siologists ought, likewise, in examining the structure of the animals 1 am now to treat 

 of. the Tortoise-tribe, to have suspected that this function was not performed in them 

 as it is in us. Yet these hints given by this anomalous structure have either been 

 neglected or made an improper use of, and the manner of their respiring remains 

 in the greatest obscurity to the present hour. Before I proceed to show the present, 

 state of our knowledge on this subject, by giving the opinions of the celebrated 

 anatomists and physiologists who have written upon it, I will just observe that, as 

 the impossibility of respiration being performed in the frog-tribe, in the usual man- 

 ner, consists in the absence of the ribs and diaphragm, so here the immobility of 

 the whole bones of the trunk, and absence of the diaphragm, form the insuperable 

 hindrance, and not a deficiency of solid parts as in the preceding; for a modifica- 

 tion of the ribs and sternum here envelops the avhole animal. The diaphragm, 

 though said by some to exist, is really wanting. Blasius, however, asserts its 

 existence, and describes it thus: "Diaphragma insigne admodum, oblique a pectoris 

 anteriore inferiores<me parte sursum adscendet, lateribus primo, hinc dorso firmiter 

 adhserens; altiorem adeoque situm in posticis obtinet, quam in anticis, contra ac in 

 homine, canibus bobus aliisque animalibus ohservamus, ubi anteriora sublimem 

 majis locum habent posterioribus. Membranosum hoe totum notatur, similiter ac 

 in avibus variis deprehendimus, nullis fibris carneis manifesto gaudens. Distinguil 

 equidem thoraeem a ventre inferiore, ast non sit in animalibus aliis: Pulmones enim 

 cum hie sese in hoc magis, quam illo ventre exhibeant magne parte, diaphragmate 

 hand includuntnr, imo vix aliqua parte. Extcndit sc supra hepar partesque alias 

 ipsi adsitas, usque ad vesicam urinariamcui valide adeo uniturtota superficie supe- 

 riore ut non nisi magno artificio separari queat, Superius pericardio jungitur." 

 Bnt I am convinced he has taken the peritonaeum for it. I have sought for it in 

 vain, as well as other zootomists ; neither (iotwald nor Wallbaum has observed it, 

 and the French academicians, who dissected one near five feet long, say, that "la 

 tortue a non seulement son ecaille, qui lui sont lieu de thorax, absolument immobile, 

 mais nous no lui avons trouve n'y de diaphragme, n'y d'autres parties qui puissent 

 supplier a ce 111011x01110111." This deficiency of the requisite mechanism for respira- 



