vitreous, the simultaneous performance of the two operations may cause internal hæmorrhage or collapse of the eye.

As a rule, then, the eye can more easily bear the operation when thus divided into two periods, and the different stages of the operation can be performed with more regularity and precision.

In old people I perform iridectomy and the subsequent flap downwards, and find the optical effects perfectly satisfactory; and in middle-aged persons, where regard must be had to appearances, I make them upwards. In either case I perform iridectomy exactly in the vertical meridian of the eye, so that the coloboma iridis shall correspond with the centre of the subsequent corneal section. The extraction is done as follows:

The patient being in a recumbent position upon a high couch, and the eye-lids being held aside by an assistant, I stand behind the patient, operating with the right hand on the right eye and with the left hand on the left eye. Fig. 8 shows the right eye operated on by a superior flap thus:

1. With the right hand I fix the globe by means of the pique de Pamand, which I consider the most suitable instrument; with the narrow Beer's knife in my right I enter the external margin of the cornea close to its sclerotic junction, perpendicular to the surface, as if wishing to reach the iris, in order to prevent the knife running between the layers of the cornea, and also in a downward direction, after Graefe's example, in order to enlarge the internal opening. After the point is seen in the anterior chamber, I carry the

handle backwards and pass to the counter-puncture, which is made directly opposite on the inner side. The points of puncture and counter-puncture are so made that the corneal flap extends to a line more than onethird of its circumference. The knife is then pushed on in a plane parallel to the iris, until the corneal section is nearly completed, when its edge is inclined a little backwards, so as to carry it under the conjunctiva, and it is then withdrawn, leaving a conjunctival bridge in the centre.

2. At this stage I take entire charge of the eye, as shown in Fig. 9. My two fingers of the left hand serving the purpose of a speculum, I order the patient to look down, and introduce one blade of the probe-pointed scissors in the track of the knife, and, carrying it to the conjunctival flap, divide it. When operating on the left eye I must here change my position, as the scissors cannot conveniently be used with the left hand, and it is not advisable to divide the conjunctiva with the knife, as it is apt to peel off.

3. The capsule is then largely opened with the cystotome. To facilitate this process, gentle pressure with my fingers upon the ball is necessary to make the capsule tense.

4. After a few seconds of rest, I seize a fold of the upper eyelid between my fingers (Fig. 10), and the lower I depress with the other thumb, and, directing the patient to look down, I exercise pressure on the lower part, exactly in the vertical meridian facing the middle of the coloboma iridis, and with the other fingers through the eyelid I press upon the wound to make it gape, when

the cataract advances through the corneal and conjunctival flap.

Due attention must be paid to this direction: pressure must be made at the point just indicated, otherwise the lens is pushed sideways, and may rupture the hyaloid or damage the ciliary processes. This is, indeed, the most critical stage of the operation, for the surgeon must have his art literally at his fingers' ends. If inordinate pressure is used, the vitreous may come out and the lens fall backwards. The pressure must be steady and graduated, and with due co-operation of both hands. If the cataract be found adherent (which can be easily diagnosed beforehand), I introduce the hook in the same manner as I introduce the cystotome, first in a horizontal direction; with it I lacerate again the anterior capsule, to make sure that there is no impediment from that source; then I slip it flatly behind the lens, turn the point forwards, and draw the lens out. If cortical fragments remain behind, the ordinary friction and sliding manœuvre, as adopted in Graefe's operation, is used to extrude them; should this fail, a small curette is used.

A glance at Fig. 9 will show the advantages of this method.

1. Previous iridectomy prevents many risks during and subsequent to the operation, as already pointed out.

2. No contracted pupil preventing its exit, the lens can be extracted by a smaller incision than one-half of the circumference, as shown by the equatorial line in the same figure; indeed, a section of this extent has no tendency to gape, as can be, readily proved by section on