622 



UTERUS AND ITS APPENDAGES. 



is to be found in the tube. According to 

 Schrceder, a decidua is here formed in tubal 

 pregnancy, notwithstanding that in the walls 

 of the tube glandulae utriculares are entirely 

 wanting. The villi are here embedded in 

 little hollows of the decidua, upon whose 

 walls the blood vessels terminate in open 

 mouths, and thus the blood is poured out 

 into the placenta. The decidua is, indeed, in 

 this case firmer, and does not exhibit so many 

 valvular openings as are present in an ordi- 

 nary placenta ; probably from the absence of 

 the utricular glands. In this case, also, an 

 epithelial layer derived from the decidua 

 covers the villi, and serves at the same time 

 as a means of junction between the parts.* 



Associated usually with the abnormal deve- 

 lopment of the ovum in the oviduct is the for- 

 mation of a decidua in the uterus, the nature of 

 which structure will be considered in a subse- 

 quent portion of this article (pp. 635. 652). 



And here it naturally occurs to inquire into 

 the probable causes of the development of 

 the ovum in a situation so unfavourable to its 

 further and complete evolution. Since, not- 

 withstanding the wonderful power of adapta- 

 tion which is in these cases exhibited by the 

 parts immediately surrounding and containing 

 the ovum, it is plain that the oviduct how- 

 ever altered, yet, on account of its peculiar 

 form and texture, can but inadequately supply 

 the offices of a uterus. It can serve but im- 

 perfectly for the nutrition and protection of 

 the foetus, and not at all for its expulsion, 

 even should the latter reach the term of its 

 dependent or intra-uterine life. 



One of the most remarkable circumstances 

 relating to this curious subject, is the fact 

 first noticed, I believe, by Dr. Oldham, that in 

 a large number of cases of tubal gestation, the 

 corpus luteum, correspondiug with the ovum 

 impregnated, is found in the ovary of the op- 

 posite side to that of the tube in which the 

 ovum is developed. Thus if the left Fallo- 

 pian tube contains the ovum, the right ovary 

 will often display the corpus luteum of a cor- 

 responding date, and vice versa. Not being at 

 first aware of Dr. Oldham's observation, I had 

 myself noticed the same circumstance in re- 

 peated instances, and had arrived at the same 

 conclusion as he has done in explanation of 

 it, namely, that at the time of the ovum 

 quitting the ovary, the tube of the one side 

 embraced the opposite ovary, and conducted 

 away the ovum, which being impregnated in 

 the ordinary way, and then being delayed at 

 the angle formed by the bending of the tube, 

 has its further progress obstructed at that 

 point until it attains too great a size to ad- 

 mit of its subsequently passing the lower 

 orifice and entering the cavity of the uterus. 



If it be objected that this explanation is 

 not satisfactory, because it assumes the ap- 

 parent improbability of the fimbriated ex- 

 tremity of one Fallopian tube being able to 



* Upon this point I do not here give any obser- 

 vations of my own, as I am preparing these for 

 publication in another form. 



grasp the opposite ovary, then I can point to 

 a preparation in the Cambridge University 

 Anatomical Museum *, in which both the 

 Fallopian tubes grasp the same ovary to which 

 their extremities are affixed by morbid ad- 

 hesion. 



Another and very different explanation of 

 this remarkable circumstance of the impreg- 

 nated ovum and corresponding corpus luteum 

 being found on opposite sides, has been given 

 by Dr. Tyler Smith f , who believes that the 

 ovum, after descending the Fallopian tube of 

 one side, traverses the upper part of the 

 uterine cavity, and ascends the opposite ovi- 

 duct, where it becomes developed. I might 

 also furnish the advocates of this doctrine 

 with an argument founded upon a most in- 

 teresting and curious observation of Bischoff,. 

 which appears to have been overlooked, but 

 which would at first sight seem to support 

 this view. Bischoff, in his essay on the de- 

 velopment of the ovum in the dog and rabbit, 

 frequently noticed a remarkable apportioning 

 of the ova between the two cornua of the 

 uterus, so as to equalise their number on 

 the two sides, when these had been ori- 

 ginally unequal, as shown by the number of 

 corpora lutea found in the ovaries. Thus, 

 in the case of a bitch whose right ovary ex- 

 hibited one, and the left ovary five corpora 

 lutea, each half of the uterus contained three 

 ova, so that two of the ova must have tra- 

 velled across from the right to the left side. 

 But it must be observed, that in the cases 

 recorded by Bischoff the ova never ascended 

 the Fallopian tube, but only travelled from 

 one cornu of the uterus to the other. 



When, therefore, we take into considera- 

 tion the great difference between the solid 

 uterus of man and the intestine- like organ of 

 the mammalia, on which these observations 

 were made, there appears to be great diffi- 

 culty in supposing that the ovum could after 

 once arriving at the uterus again enter an 

 oviduct, especially when also it is remembered 

 that while the conical form of the Fallopian 

 tube, whose smallest aperture is towards the 

 uterus, constitutes a provision for ensuring 

 the arrival of the ovum there, this arrange- 

 ment would greatly diminish the possibility of 

 a retrograde movement taking place in the 

 human subject, if indeed it would not alto- 

 gether prevent it. 



But to those cases of tubal gestation in 

 which the corpus luteum is found in the cor- 

 responding ovary, neither of these explanations 

 would apply. Here it is only necessary to 

 suppose, that either the developmental changes 

 already described as occurring normally to the 

 ovum in the tube, have proceeded more rapidly 

 than usual, or else, that the ovum, having been 

 accidentally delayed for a longer time than 

 ordinary in transitu, had acquired too great a 

 magnitude to admit of its passage by the ute- 

 rine orifice, even admitting, as some have 

 supposed, that this orifice may, to a certain 



* No. 722. 



t Lancet, No. xv. vol. i. 1856. 



