It slowly began to dawn on me that I had been staring at her for an impossible amount of time. Lost in my thoughts, lost in the sight of her. But her face didn't look offended or amused. It almost looked as if she were studying the lines of my face, almost as if she were waiting. I wanted to take her hand. I wanted to brush her cheek with my fingertips. I wanted to tell her that she was the first beautiful thing that I had seen in three years. The sight of her yawning to the back of her hand was enough to drive the breath from me. How I sometimes lost the sense of her words in the sweet fluting of her voice. I wanted to say that if she were with me then somehow nothing could ever be wrong for me again. In that breathless second I almost asked her. I felt the question boiling up from my chest. I remember drawing a breath then hesitating--what could I say? Come away with me? Stay with me? Come to the University? No. Sudden certainty tightened in my chest like a cold fist. What could I ask her? What could I offer? Nothing. Anything I said would sound foolish, a child's fantasy. I closed my mouth and looked across the water. Inches away, Denna did the same. I could feel the heat of her. She smelled like road dust, and honey, and the smell the air holds seconds before a heavy summer rain. Neither of us spoke. I closed my eyes. The closeness of her was the sweetest, sharpest thing I had ever known.

The full moon, well risen in a cloudless eastern sky, covered the high solitude with its light. We are not conscious of daylight as that which displaces darkness. Daylight, even when the sun is clear of clouds, seems to us simply the natural condition of the earth and air. When we think of the downs, we think of the downs in daylight, as with think of a rabbit with its fur on. Stubbs may have envisaged the skeleton inside the horse, but most of us do not: and we do not usually envisage the downs without daylight, even though the light is not a part of the down itself as the hide is part of the horse itself. We take daylight for granted. But moonlight is another matter. It is inconstant. The full moon wanes and returns again. Clouds may obscure it to an extent to which they cannot obscure daylight. Water is necessary to us, but a waterfall is not. Where it is to be found it is something extra, a beautiful ornament. We need daylight and to that extent it us utilitarian, but moonlight we do not need. When it comes, it serves no necessity. It transforms. It falls upon the banks and the grass, separating one long blade from another; turning a drift of brown, frosted leaves from a single heap to innumerable flashing fragments; or glimmering lengthways along wet twigs as though light itself were ductile. Its long beams pour, white and sharp, between the trunks of trees, their clarity fading as they recede into the powdery, misty distance of beech woods at night. In moonlight, two acres of coarse bent grass, undulant and ankle deep, tumbled and rough as a horse's mane, appear like a bay of waves, all shadowy troughs and hollows. The growth is so thick and matted that event the wind does not move it, but it is the moonlight that seems to confer stillness upon it. We do not take moonlight for granted. It is like snow, or like the dew on a July morning. It does not reveal but changes what it covers. And its low intensity---so much lower than that of daylight---makes us conscious that it is something added to the down, to give it, for only a little time, a singular and marvelous quality that we should admire while we can, for soon it will be gone again.

In the deep, wet tangled, wild jungle where even natives won't go is a mystical, dangerous river. The river's got no name because naming it would make it real, and no one wanted to believe that river be real. They say you get there only inside a dream-but don't you think of it at bedtime, now, 'cause not everyone who goes there be able to leave! That jungle canopy, it so leafy true daylight can never break in the riverbank, it be wet muck thick with creatures that eat you alive if you stay still too long. To miss that fate, you gots to go into the black water. But the water be heavy as hot tar; once you in, it bind you and pull you along, bit by bit, 'til you come to the end of the land, and then over the water goes in a dark, slow cascade, the highest falls in the history of the world ever. There be demons in that cascading water, and snakes, and wraiths that whisper in your ears. They love you, they say. You should give yourself to them, stay with them, become one of them, they say. 'Isn't it good here?' they say. 'No pain, no trouble.' But also no light and no love and no joy and no ground. You tumble and tumble as you fall, and you try and choose, but your mind be topsy-turvy and maybe you can't think so well, and maybe you can't choose right, and maybe you never wake up. "It felt like that," I tell Tootsie, "even after you got me out and Scott moved me to Highland. I couldn't choose. I couldn't shut out the wraiths...But you would say, 'Hang on, sweetie,' and Scottie would say, 'I miss you, Mama,' and Scott would hold me, just hold me and say nothing at all." Tootsie snorts. "Scott was useless the whole while." "Scott was in the river, too.

In describing a protein it is now common to distinguish the primary, secondary and tertiary structures. The primary structure is simply the order, or sequence, of the amino-acid residues along the polypeptide chains. This was first determined by [Frederick] Sanger using chemical techniques for the protein insulin, and has since been elucidated for a number of peptides and, in part, for one or two other small proteins. The secondary structure is the type of folding, coiling or puckering adopted by the polypeptide chain: the a-helix structure and the pleated sheet are examples. Secondary structure has been assigned in broad outline to a number of librous proteins such as silk, keratin and collagen; but we are ignorant of the nature of the secondary structure of any globular protein. True, there is suggestive evidence, though as yet no proof, that a-helices occur in globular proteins, to an extent which is difficult to gauge quantitatively in any particular case. The tertiary structure is the way in which the folded or coiled polypeptide chains are disposed to form the protein molecule as a three-dimensional object, in space. The chemical and physical properties of a protein cannot be fully interpreted until all three levels of structure are understood, for these properties depend on the spatial relationships between the amino-acids, and these in turn depend on the tertiary and secondary structures as much as on the primary. Only X-ray diffraction methods seem capable, even in principle, of unravelling the tertiary and secondary structures.[Co-author with G. Bodo, H. M. Dintzis, R. G. Parrish, H. Wyckoff, and D. C. Phillips]