"It's the same the whole world over, it's the poor wot gets the blame. It's the rich wot gets the pleasure..."

We were on a "toughening course," living under canvas in the depths of Shropshire, and this was one of the occasions when we were all gathered together—hundreds of sunburned men—in a huge marquee waiting to be adressed by a visiting air commodore.

Before the great man arrived the platform was occupied by a lascivious sergeant who was whittling away the time by leading us in a succession of bawdy ditties accompanied by gestures. "It's the rich wot gets the...," but instead of "pleasure" he made a series of violent pumping movements with his forearm.

I was intrigued by the reaction of the airman on my right. He was a slim, pink-faced lad of about nineteen and his lank fair hair fell over his face as he jumped up and down. He was really throwing himself into it, bawling out the indelicate words, duplicating the sergeant's gesticulations with maniacal glee. He was, I had recently learned, the son of a bishop.

We had been joined on this course by the Oxford University Air Squadron. They were a group of superior and delicately nurtured young men and since I had spent three full days peeling potatoes with them I had come to know most of them very well. "Spud bashing" is an unequalled method of becoming familiar with one's fellow men and as, hour after hour, we filled countless bins with our produce, the barriers crumbled steadily until at the end of three days we didn't have many secrets from each other.

The bishop's son had found something hilarious in the idea of a qualified veterinary surgeon leaving his practice to succour his country by removing the skins from thousands of tubers. And I, on the other hand, derived some reward from watching his antics. He was a charming and likeable lad but he seized avidly on anything with the faintest salacious slant. They say parsons' sons are a bit wild when let off the leash, and I suppose an escapee from a bishop's palace is even more susceptible to the blandishments of the big world­.

I looked at him again. All around him men were yelling their heads off, but his voice, mouthing the four-letter words with relish, rang above the rest and he followed the actions of the conducting sergeant like a devoted acolyte.

It was all so different from Darrowby. My early days in the RAF with all the swearing and uninhibited conversation made me realise, perhaps for the first time, what kind of community I had left behind me. Because I often think that one of the least permissive societies in the history of mankind was the agricultural community of rural Yorkshire in the thirties. Among the farmers anything to do with sex or the natural functions was unmentionable.

It made my work more difficult because if the animal's ailment had the slightest sexual connotation its owner would refuse to go into details if Helen or our secretary Miss Harbottle answered the 'phone. "I want the vet to come and see a cow," was as far as they would go.

Today's case was typical and I looked at Mr. Hopps with some irritation.

"Why didn't you say your cow wasn't coming into season? There's a new injection for that now but I haven't got it with me. I can't carry everything in my car, you know."

The farmer studied his feet. "Well, it was a lady on t'phone and I didn't like to tell 'er that Snowdrop wasn't bullin'." He looked up at me sheepishly. "Can't you do owt about it, then?"

I sighed. "Maybe I can. Bring me a bucket of hot water and some soap."

As I lathered my arm I felt a twinge of disappointment. I'd have liked to try that new Prolan injection. But on the other hand there was a certain interest in these rectal examinations.

"Hold her tail, please," I said, and began to work my hand carefully past the anal ring.

We were doing a lot of this lately. The profession had awakened quite suddenly to the fact that bovine infertility was no longer an impenetrable mystery. We were carrying out more and more of these examinations, and as I say, they had a strange fascination.

Siegfried put it with his usual succinctness one morning.

"James," he said. "There is more to be learned up a cow's (bum) than in many an encyclopedia."

And, groping my way into this animal, I could see what he meant. Through the rectal wall I gripped the uterine cervix, then I worked along the right horn. It felt perfectly normal, as did the fallopian tube when I reached it. In another moment the ovary rested between my fingers like a walnut; but it was a walnut with a significant bulge and I smiled to myself. That swelling was the corpus luteum, the "yellow body" which was exerting its influence on the ovary and preventing the initiation of the normal oestral cycle.