By Wireless to The New York Times

WITH CHINESE - AMERICAN FORCES AT MYITKYINA, in Burma, May 17 (Delayed).

For Brig. Gen. Frank Merrill's American Raider detachment this week's attack on Myitkyina is the climax to four months of marching and combat in Burma jungles. No other American force except the First Marine Division, which took and held Guadalcanal for four months, has had as much uninterrupted jungle fighting service as Merrill's Raiders.

No other American force anywhere has marched as far, fought as continuously or has had to display such endurance, as General Merrill's swift-moving, hard-hitting foot soldiers.

When the Americans attacked Myitkyina they had behind them 800 miles marching over jungle and mountain roads and tracks. They had already fought four major engagements and since early March had been in almost daily combat with large and small Japanese forces, Before the Burma Raiders had reached Myitkyina they had killed more than 2,000 Japanese for losses to themselves of only a fraction of this number.

RAIDERS STARTED IN FEBRUARY

A specially organized detachment made up of men who had volunteered for the jobs out of units who had seen service in the Solomons and New Guinea or who had received special training in jungle warfare in the Caribbean area. Merrill's Raiders set out for their grueling assignment from Ledo in Assam early in February.

After a three weeks' march over the Naga Hills and into the Hukawng Valley the Raiders made a wide sweep around the Japanese flank at Maingkwan and stabbed into the rear of the enemy at Walawbum. Establishing themselves across the road, the Americans slaughtered more than 600 Japanese who sought to escape southward from the frontal attacks and flanking thrust of Lieut. Gen. Joseph W Stiwell's Chinese forces north of Walawbum.

The Raiders then set out through the steaming forest of the Hukawng Valley for there next engagement.

Part of the Raiders, under Lieut. Col. William Osborne of Los Angeles, Teamed with a Chinese detachment, climbed through the mountains at the south end of Hukawng Valley east of the main road, fighting small groups of Japanese all the way, and established a road block far in the Japanese rear at Laban near Shaduzup, forty miles south of Walawbum. After inflicting heavy losses on the Japanese, paving the way for another advance of General Stiwell's main forces, Colonel Osborne's men withdrew.

BIG OUTFLANKING MARCH

Meanwhile the rest of the Raiders under General Merrill made a prodigious outflanking left end march of seventy miles in three days, most of the way over rugged timbered mountains and set another road block at Inkangatawng, fifteen miles south of Shaduzup. armed and organized only for hit and run blows, General Merrill's force withdrew after twenty-four hours when the Japanese produced overwhelming strength against them.

Pulling back into the hills, closely pursued by a Japanese column that had the assignment of making a Merrill-style raid of its own against General Stiwell's forces north of Shaduzup, a battalion of General Merrill's men stood at Npum Ga, and engaged the enemy column. Here a fourteen-day battle was fought, the fiercest the Raiders had up to the time of the Myitkyina attack.

At one stage the battalion was surrounded by Japanese and pounded with artillery, but other Raider units broke through and relieved their comrades. The Japanese force was virtually annihilated and the enemy's plans were shattered.

After a few days of reorganization and integration with Chinese units, Merrill's Raiders set out for their biggest job, the assault on Myitkyina.

GAUNT ON SCANT RATIONS

Lean, gaunt bodies, bearded faces and hollow eyes tell the story of the physical drain their terrific jungle campaign has been for the Raiders. Most of the time they have lived on standard K rations, little packaged meals of tinned cheese, ham and eggs, pork, chocolate, fruit bars and crackers.

Occasionally at rest stages they have been stationary long enough to receive bulkier and more varied foods. All rations and all other supplies have been dropped by planes and this has enabled the Merrill forces to go anywhere with out regard for an overland line of communications.