In 16 subjects of tall stature, the urethra measured The collective average is therefore nearly 84- inches, and the respective averages would stand thus: — For those of tall stature, it would be Sin. 91.
For those of middling stature - Sin. 21, For those of short stature - - Sin. 31.
Lisfranc examined the urethra in twelve adults, and he found its length to vary from 9 to 10 inches. In a negro it measured 12 inches.
M. Petrequin has collected the various measurements of the canal, as given by the French writers on this subject, by which it appears that the estimated length varies from 51 inches to 12 inches. Petrequin con ducted his own examinations with both straight and curved instruments. With the straight instrument he found the length of the urethra between 61 and 61 inches, whilst with a curved instrument it measured from 64 to 7 inches. The difference he explains by the fact, that, inasmuch as the urethra is not recti linear, a straight instrument cannot be passed through it without effacing the angle between.
the bulbous and membranous portions of the canal.* Mr. Briggs observing that most of his pre decessors had examined the length of the urethra after death, made a series of examina tions of the canal in the living subject; and he adopted the following mode of examina tion:— He introduced into the bladder a ca theter without a stilet, on the stem of which was marked a graduated scale of inches and fractional parts, measured from the eye of the instrument. He observes, "as soon as the urine begins to flow from the catheter, which has only one eye, the line marked on the stem corresponding with the external meatus will necessarily indicate the exact length of the canal, or the from the meatus to its termination in the bladder. Of sixty persons in whom the urethra was measured thus, the length was found to vary from 6/ to 81 inches. In eight instances, or rather less than one seventh of the whole (twenty of them being persons of short stature, or not exceeding 5 feet 4 inches in height), the length of the urethra was found to be under 7 inches. In forty-five instances, or three-fourths of the number, i. e. in persons of middle stature, the measurement was found to be between 7 and 8 inches, and in a few it exceeded 8. In some
instances of very corpulent subjects, at an advanced age, the urethra was found to be 10 inches in length." He considers the average length of the passage to be 71 or 7/ inches, the external parts being in a natural condition, neither hanging in a loose, flabby state, nor unusually retracted. Briggs found the pro portions of the various parts of the canal to stand relatively thus : — from the orifice to the membranous part, 61inches ; from thence to the bladder, 1 / inch =8/ inches. As there was no stretching of the penis in the examina tions thus made, it is easy to reconcile the discrepancies between Briggs's and Whately's Measurements.
Of the relative length of the different por tions of the canal, M. Petrequin cites the fol lowing authorities: — The prostatic portion measures, according to Boyer, 15 or 16 lines ; Littre, 15 lines ; Ducamp and Blandin, from 12 to 15; Senn, 13; J. Cloquet, 15. M. Petrequin agrees with Lisfranc, that the most exact measurement is from 8 to 11 lines.
Boyer estimates the length of the mem branous portion at 12 lines ; Ducamp, from 9 to 12; Blandin, at 10; Lisfranc, from 7 to 11. M. Petrequin has found it to vary from 6 to 9 lines, when measured by its central axis ; its upper surface measuring from 8 to 10 lines, its under surface from 4 to 5 and sometimes 6, the difference arising from the projection of the bulb beneath. The mean length of the prostatic and membranous portions taken to gether is, according to Malgaigne, 13 lines, but it varies from 11 to 15 lines. Petrequin has found it to vary from 14 to 18 and some times 20. As to the bulbous and pendulous portions of the urethra, their rectilinear mea surement is 6 inches or 6 inches and 10 lines, and the curvilinear 5 inches or 5 inches and 4 lines, Diameter.— In diameter, also, the urethra varies according to age: thus in the young sub ject it is small ; indeed its diameter increases in proportion to the age of the individual; and in the aged, partly in consequence of the flac cidity of the parts surrounding it, partly from the loss of contractility in its own tissue, its capacity becomes immensely increased, so that it will readily admit a catheter of half an-inch bore, and the escape of fragments of stone of equal size.