Introduction The 21 illonosomic strains of the hard red spring wheat variety, Chinese Spring (Sears 1954), have been used to develop similar strains in other varieties. The monosomic condition is transferred to a variety by initial crosses between each of the 2 1 Chinese S ~ r i n e illonosomics and the reci~ient varietv. followed L U I J ' by a series of baclccrosses to recover the genotype of the recipient variety. In developing and maintaining monosomic strains, specific chromosomes are transmitted as univalents through successive generations. Since only a few chromosomes are ltnown to ~ r o d u c e ~ h e n o t v ~ i c effects in the monosomic state. infor1 I J 1 illation concerning chromosome morphology in different varieties is needed in ~. . . identifying monoson~ics. Sasalti et nl. (1963) have presented the lengths and characteristics of inetaphase I monosomes in the hard red winter variety, Cheyenne. Similar inforhation will be reported in this paper for another winter 6ariety, Wichita, using observations at metaphase I and anaphase 11. Throughout this study emphasis was placed on factors involved in sampling and measurement which might contribute to variations in chromoson~e length. Materials and Methods The inonosomic strains for the 21 different chromoso~nes of the hard red winter variety, Wichita C.I. 11952, were used in the present study. These strains had been derived by crossing Wichita as the male parent with each of the 21 inonosomic strains of Chinese Spring developed by Dr. E. R. Sears. Repeated baclccrossing of the derived monosomic plants to Wichita followed. At the time of this study five or six bacltcrosses had been con~pleted for all the chromosomes except 3B and jD, which had been bacltcrossed twice. Seeds of the monosomic strains were planted in 7-inch pots of soil in November, 1960, and the plants were grown in a plastic greenhouse. Artificial lights were provided during the flowering period. Following a vernalization period, the day temperature was controlled at 65 to 75°F. when the outside temperature was lower, and the night temperature at 50 to 55°F. Ample water and fertilizer were applied. Based on the findings of Sasalti et nl. (1963), a satisfactory method of sampling for statistical efficiency was found to include two monosomic plants for each chron~osome, four heads per plant, two slides per head, and two measurements per slide. In order to separate the date-of-sampling effects from head effects, an effort was made to collect saillples on two different dates from the same plant. taltine two heads on each date. I ' U Thus, for each sampling period, the aim was to obtain 16 measurements for each lcind of monosome, or a total of 336 measurements for the 21 monosonles. This was most nearly achieved for the metaphase I stage at the first