CHEMICAL STRUCTURE AND STIMULATION 167 



MATERIALS AND METHODS 



All of the data refer to the usual behavioral assays for sugar sensitivity 

 used by Dethier (1955 and earlier) on the adult blowfly, Phormia regina 

 Meigen. Much of the data to be discussed is that of Hassett et al (1950) 

 and Dethier (1955). For the present purposes some new compounds were 

 obtained and assayed. The sensitivity of a population of 30 to 120 flies 

 was assessed for each new compound in relation to the sensitivity of that 

 population to an equilibrium solution of glucose. 



Compounds 1 and 2 in Table 1 had previously been tested by Dethier 

 (1955), but were retested. Alpha glucose is the usual commercial form, and 

 beta glucose was prepared by crystallization from hot acetic acid (m.p. = 

 149°C). The gamma and delta lactones of gluconic acid were purchased 

 (Pfansteil). Each of the four compounds mentioned were examined for 

 purity and rate of mutorotation by polarimetry. These compounds were 

 then assayed on the blowfly under similar conditions soon enough after 

 solution in water so that 98^ per cent of the solute was in the desired form 

 as calculated from the polarimetric data. Gold thioglucose was given by 

 the Scherring Research Division and was pure according to chromato- 

 graphic examination in three solvent systems (Evans and Dethier, 1957). 

 Polygalitol and arlitan were prepared from a sample given by the Research 

 Division of the Atlas Powder Company. An aqueous solution containing 

 between 80 and 85 per cent of a mixture of glucitol, polygahtol, and arlitan 

 was provided. Chromatography of the sample separated the three com- 

 pounds. Glucitol was identified by its migration with authentic glucitol 

 (sorbitol-Pfansteil). The two anhydrides were identified by their dif- 

 ferential reactivity with periodate (Evans and Dethier, 1957). Chromato- 

 graphy on thick electrophoresis paper and subsequent elution provided 

 large enough samples of the pure materials for assay. 2-deoxy-, 2-0- 

 methy-, and 3-0-methyl-glucose were a gift from Dr. N. K. Richtmeyer. 

 Mono- and di-isopropylidene glucose (1,2 and 1,2,5,6 mono- and di- 

 acetone glucose respectively) were prepared according to Mehltretter et al. 

 (1951). The melting points were 159-162 and 108-1 lO'C respectively. 

 Dethier (1955) had reported that diacetone glucose was stimulating. From 

 theoretical considerations and later tests of the authentic material (see 

 below), this seemed highly improbable. Accordingly, the melting point of 

 the " diacetone glucose " used by Dethier was determined ; it was 150- 

 153°C in contrast to IIO-IITC of the pure material (Bates et al, 1942). 



All of the polyols, sugars, and sugar derivatives referred to below are of 

 the D-series unless stated otherwise or the designation is not applicable. 



RESULTS AND DISCUSSION 

 Multiple Combining Sites for Polyols 

 The initial stimulus for the present study derived from the unsatisfying 



