6,1 PFLA BASS ANA. 



On tliG inside i-f tlie tulj(;s at the extreme end, are wide tymiianifenn memliranes. tliat continue about 

 tlie same vndth. and occupy very nearly the entire inside of tiie broncliials, for about six Iialf rings, at a 

 point near 0. Fig. 7. Tlien they suddenly narrow to a slight division between ihe bronchial rings, and 

 so cdutinue t-j the lung.s: Fig. (!, D, p. being the wide i)ortinn nf the wide tympaniform. and e, the narrow. 



At the puint ivhere the tympanifVjrms narrow a membranou.s nin.scle liegins, stretching acmss from 

 tube to tube, aud adhering to them along the lower edge of the narrow tympaniforms. Fig. 6, A. o, b. b. 



Tlie muscle is thin, but is strengthened by two ridges of thick fiber. Fig. fi. A. Tlic function of 

 this muscle is to draw downward the uj .per portions of the tubes, and thus render tense the wider portions 

 of the tympaniforms. 



The upper portions of the tympaniforms have their beginning in the acute angle of the bronchial tubes, 

 Fig. 7, 0, where a diagramatic section is given: they are attached to an os transversale, seen in the unshad- 

 ed portion. Fig. C, J), between p and i, and this bone bears a very narrow semi-lunar memlirane. so narrow, 

 in fact, as to be nearly or wholly functionless, see Fig. 0, I>. i. 



The thyroid glands are rather better developed than in the majority of liirds, especially on the left. Fig. 

 ](), A, which is attached to the carotid artery. Fig. Id, by its upper portion. Fig. 1(», and is considerably 

 elongated, and on its upper portion is a second division of the gland, yellowish in color and adhering closely 

 to the larger portion. Fig. lt>, A. 



The oesophagus is dilated to a great degree: it is lii.Oi) long: tlierc are i>romineiit folds of the mucous 

 membrane, running longitudinally the entire length of the interior, and these merge into the A\ide ]irovcu- 

 triculus, Avithout any constriction. 



The pruventnculus. Fig. 1 1 . a. is Avidc, measuring l..-)i i hi diameter and is about 4.(:01ong, with the glands 

 of the secreting surface arranged in a peculiar manner, these being divided nito two sections, both triangu- 

 lar in form, the upper o. ."■)(.) by 2.(»(», and the lower smaller, and proportionately narrower, about o.OU by 1.00. 

 Sec Fig. I), a, being a diagram of the upper, and c of the lower, cluster of glands, about one-fourth the size 

 of life. Tlie glands arc simple and cylindrical in form, see d, where is given a life size cut of a cluster. 



The stomach. Fig. 11. b, is continued from the proventriculus without any constriction, but it becjmes 

 narroAvcr a little back of the junction. Thus it is a mere sac, 2.00 long by 1.00 wide; the walls are thhi, and 

 are lined with a soft mucous membrane much wrinkled. Near pyloric opening these wrinkles become en- 

 larged into folds, two of Avliich overlie the orifice, see Fig. S, where is shown the opening, and the folds which 

 overlie it. The intestine is ]irovided with a sjihincter muscle, just within the entrance, liy which the orifice 

 may lie coniplctcly closed. 



The intestine emerges ii-oiii the stomach about one-half its length. Fig. 11, thus the terminal jiortion 

 becomes the cul-de-sac. li. 'Tlie intestine pushes outward for about l.Olt then turns upward to form the fold 

 of the duodenum. 



The pancreas. Fig. 11, dd. is i.T'i in length, long enough to reach the entire length of the fold, Imt as it 

 begins al)out 2.!iO from its termination, it extends some distance along the intestine. 



The intestines are G4.(>() long, and are not large in diameter, measuring only about .HO. The coeca, 

 Fig. 11. c. are very small. Imt the blind ends are detached from the intestines and are jiointed. One is lar- 

 ger than the other. 



The spleen is a i)yramidical-slia]K'd body, lying between the intestines and the anterior iiortion of the 

 ])roveiitrlculus. 



The gainict li'om wliicli tliis ili<s('<-tioii was made was evidently an aged siiccimcii: it 1 icing. -i il'iiiale with 

 tlie ovaiics nearly dcplrtcd. tliciX' lieiiig about a hundi'cd and I'ony nqiturrd caiisiilcs. among whicli arc in- 

 tersiiersed a comparatively few ovules. As a ruptured capsule indicates most surely that an egg has lieen 

 doiiosited. it is reasonalile to sup]iosc that this gannet had laid something like one hundred and forty eggs, 

 and as there is Init one egg laid in a season, this would give an approximate great age to the bird, even if 

 we allow fir occasional accident to an egg, when a second specimen would be deposited that season. 



Fig. 1'-' is a drawing of a young of the Common (.iannet, life size, about Iavo days old, and is one of the 

 sperinu'us iif which I have spoken on ]iage ■'I'l. It will l)e seen that there are very few feathers on the bird. 

 yet on the young of Cory's Gannet. Sula cor^'i, a tropical species, the feathers are comparatively develojied. 

 Seeing. !'■'', where I have given a cut of Cory's Gannet about two days old. The adult of the Common 



