_Difficulty and importance of the subject.--Diagnosis in the early months.--Auscultation.--Changes in the vascular and nervous systems.--Morning sickness.--Changes in the appearance of the skin.--Cessation of the menses.--Areola.--Sensation of the child's movements.--"Quickening."--Ausculation.--Uterine souffle.--Sound of the foetal heart.--Funic souffle.--Sound produced by the movements of the foetus.--Ballottement.--State of the uterine.--Violet appearance of the mucous membrane of the vagina.--Cases of doubtful pregnancy.--Diagnosis of twin pregnancy._ There is, perhaps, no subject connected with midwifery, which is of such importance, or which, from its difficulty and the serious questions it involves, demands such attentive consideration, and requires so familiar an acquaintance with every part of it, as the diagnosis of pregnancy. The responsibility which a medical man incurs in deciding cases of doubtful pregnancy, and in thus giving an opinion which may not only affect the fortune, happiness, character, but even life itself of the individual concerned, is rendered more painful by the perplexing obscurity of the circumstances under which these cases sometimes occur, being not unfrequently complicated with diseases which add still farther to the difficulty of coming at the truth, and occasionally rendered peculiarly obscure by wilful and determined falsehood and duplicity. To render this subject more intelligible to our readers, we propose first to consider the general effects which pregnancy produces upon the system, and then to describe those changes and phenomena which are _peculiar_ to this state, and which may therefore be taken as so many means of diagnosis. Under all circumstances, the diagnosis of pregnancy must ever be difficult and obscure during the early months; the development of the uterus is still inconsiderable, and the effects which it may have produced upon the system, although appreciable and even distinct, are nevertheless too capable of being also produced by other causes, to warrant our drawing any decided conclusion from them. The effects over the whole animal economy, which result from the presence and advance of this great process, are very remarkable, and show themselves in every portion of it.