ON THE ARRANGEMENT OF THE FCETAL MEMBRANES IN THE CETACEA. 493 



face of a cotyledon for the reception of the chorionic villi are only remarkable 

 dilatations of the uterine glands.' 51 ' 



In the zone-like placenta of the Carnivora, the observations of Dr SHARPEY,f 

 which Weber and Bischoff J have confirmed, have shown that two kinds of 

 glands, simple and compound, open on the mucous surface of the uterus of 

 the bitch. § After impregnation both kinds of glands dilate into pits, which 

 receive the foetal villi. The simple undergo a uniform enlargement, whilst 

 only the mouths and adjacent part of the ducts of the tubular glands are dilated 

 into pits. Jassinsky even states, || that in the bitch all the chorionic villi, without 

 exception, pass into the uterine glands, so that a double membrana propria and 

 a double epithelial covering may be recognised in connection with each villus, 

 one membrane and one epithelial layer belonging to the villus itself, the others 

 to the gland in which it is included. 



And here I may refer to the other hypothesis, to which I alluded on p. 491, 

 in explanation of the mode of production of the crypts 1" in the cetacean. 

 It may be that in the Orca also both kinds of glands exist, and undergo dila- 

 tation during pregnancy, so that the crypts of my vascular crypt layer may 

 include both the uniformly enlarged, short, simple glands and the dilated mouths 

 of the utricular glands. In the absence, however, of any knowledge of the 

 existence of the simple glands in the unimpregnated uterus of the cetacean, the 

 hypothesis previously advanced is to be preferred ; as we do know that a great 

 growth of the inter-glandular connective tissue and increase in the superficial 

 area of the uterus take place, which, if thrown into folds, would produce such 

 a crypt-like structure as has been described, without the necessity of assuming 

 the pre-existence and subsequent enlargement of the short simple glands. 



In the mammals which possess the Discoid form of placenta Leydig** has 

 observed the existence of utricular glands in the mole. Of the Rodents which 



* Henle and Pfeufer's Zeitsclirift, vol. xxi. 



■f" Op. cit., p. 1576. X Hunde Ei, plate xiv. 



§ Weber, Rolleston, and Ercolani have pointed out the presence of utricular glands in the cat. 

 I have also seen them in the badger, in which animal they closely resemble the figure and description 

 given by Bischoff of these glands in the bitch. Ercolani denies the existence of two kinds of glands 

 in the bitch's uterus, and states that only the utricular glands are present. Carl Eriedlander has, 

 however, recently made some observations (" Untersuchungen fiber den Uterus/' Leipzig, 1870), which 

 reconcile the opposite statements of Sharpet and Ercolani. Eor he points out that, whilst in the 

 quiescent condition of the uterus of this animal only the utricular glands are present, in the period of 

 heat, when the mucous membrane is swollen, and its vessels turgid with blood, simple glands are also 

 met with. 



|| Yirchow's Archiy, xl. p. 350. 1867. 



II To prevent misunderstanding I may state that Bischoff specially designates the short simple 

 glands of Sharpet as the mucous crypts,whilst the longer, branching, convoluted glands are the proper 

 utricular glands. In my description of the uterine mucous membrane of Orca, I have employed the 

 term crypts to designate all the pouches or pockets which receive the chorionic villi, whether accord- 

 ing to the above hypothesis they are the simple glands uniformly enlarged, or the dilated mouths of 

 the utricular glands. 



** Histologie des Menschen und der Thiere, p. 517. 1857. 



