After that has been done, turn the eye so the iris will be uppermost. With the tweezers pick up the pupillary margin of the iris, and with the fine-pointed scissors cut through the iris and the ciliary processes (Fig. 31); separate both from the choroid by cutting close to the posterior edge of the processes. (Fig. 32.) In doing that, cut partly through the vitreous also, but be careful not to injure the peripheral edge of the retina--ora serrata. After the iris has been separated from the choroid, cut completely through the vitreous in such a way that the lens will also be removed with the iris. (Fig. 33.) [Illustration: Fig. 34--Showing how to force glass blowpipe (A) into vitreous (B). (Page 80.)] [Illustration: Fig. 35--Showing bulging out of vitreous caused by blowing air through glass blowpipe. (Page 80.)] [Illustration: Fig. 36--Showing the vitreous (A) removed.] Holding the eye suspended by its optic nerve, force the glass blowpipe through the vitreous until it all but touches the posterior part of the retina (Fig. 34); blow gently at first, increasing the pressure until the vitreous suddenly bulges outward. (Fig. 35.) If the iris has been cut away close to the ora serrata, the vitreous will not only bulge forward, but it will fall out. If, however, it does not detach itself at once, insert the scalpel close to the choroid and with its flat side press downward until a separation occurs. Do not let the vitreous drop out too suddenly, because it may tear the retina. Let the vitreous detach itself slowly by the force of its own weight, though it will be well to hold some of its weight on the scalpel. (Fig. 36.) [Illustration: Fig. 37--A. Showing retina folded upon itself by blowing air at it through the glass blowpipe. (Page 83.)] [Illustration: Fig. 38--A. Showing folded retina suspended from its attachment, so sclerotic and choroid may be easily cut away. (Page 83.)] After the vitreous has been removed, turn the eye upward, and by blowing strongly through the blowpipe at the marginal edge of the retina, turn the retina upon itself. Repeat this until the retina lies in a small wrinkled lump at the “bottom” of the posterior part of the eye. (Fig. 37.) Invert the eye (Fig. 38) and cut away both the choroid and the sclerotic close to the optic nerve. No care need be taken in doing this until the scissors come close to the optic nerve. (Fig. 39.) [Illustration: Fig. 39--Showing the sclerotic nearly all cut away.] [Illustration: Fig. 40--Isolated retina, with optic nerve attached.]