270 School Science and Mathematics

(18) RCA SERVICE COMPANY 1960. Atomic Radiation, Part II. Radio Corpora-tion of America, Camden. 117 pages.

(19) OVERMAN, R. T. AND H. M. CLARK 1960. Radioisotope Technique. McGraw-Hill Book Company, Inc., New York. 476 pages.

(20) BOYD, G. A. 1955. Autoradiography in Biology and Medicine. AcademicPress, Inc., New York. 399 pages.

MICHIGAN COUNCIL OF TEACHERS OF MATHEMATICSNOON LUNCHEON, COBO HALL, DETROIT, MICHIGAN

SATURDAY, APRIL 24, 1965

The MCTM will hold a special luncheon honoring its Past Presidents andAdvisors at the 43rd Annual Meeting of the NCTM. The theme of the luncheonwill be the History of the MCTM. Plan to attend now. Tickets may be obtainedby writing to Mr. James Hyatt, St. Clair High School, St. Clair, Michigan. Thecost is $4.00 which includes your 1965-66 membership in the MCTM. If thereare some left, tickets will also be available at the MCTM Registration Desk,Cobo Hall, during the 43rd Annual Meeting, NCTM.

BIRDS GROW FAT TO FLY; THIN TO LAY EGGSSwallows, warblers and other long-distance travelers may have as much as

50% of their body weight stored in fat reserves when they are ready to fly onlong migrations in the spring.

This fat provides energy to the winged voyagers during long flights, across theoceans or at night when they cannot or do not stop for food.Yet these same birds can grow exceedingly thin at other times of the year,

when they are molting or losing their feathers, and also when they are repro-ducing. At these lean times of the year, the fat reserves in the birds are only fivepercent of the body weight.When captive birds are kept outside in cages, they show the same cyclic vari-

ations in their fat reserves as the wild birds. These captive birds begin to store upreserves of fat in their bodies when they are artificially stimulated with light toimitate the lengthening of daylight hours in spring, or when they are injectedwith prolactin, a hormone which stimulates development of the crop-sac inpigeons and milk production in mammals.