TARSAL PERCEPTION 



137 



pressure. From Minnich's data it seems that the general order 



of effectiveness for the four sugars tested is — saccharose and 



maltose >glucose>lactose. In other words, it is essentially the 



same as that observed both by von 



Frisch (1927, 1928) and by Kunze 



(1927) for the mouth-parts of the hive 



bee. 



In 1932 Minnich published the 

 results of experiments with the hive 

 bee, the responses being judged by 

 the extension of the proboscis. The 

 bee is able, by means of the antennae 

 or the fore leg, clearly to distinguish 

 between 64/100 M saccharose solution 

 from an equimolar solution of lactose 

 and from water. The antennae are 

 well known to function as distance 

 receptors, and it appears that they 

 are used as contact receptors also. 

 Although it seems clear from these 

 experiments that the apex of the 

 antennae bears contact chemoreceptors, 

 it is by no means certain which type, 

 of the five kinds of sensoria present, 

 actually function in the j^rocess. 



Other investigators, including Abbott 

 (1928), Anderson (1932), Crow (1932) Fig. 59. Chemoreceptor 



and Weis (1930), have confirmed and 



extended Minnich's chief results and 



conclusions, with the outcome that it 



appears quite certain that the legs of 



certain butterflies and flies, at any 



rate, are highly sensitive to chemical 



stimuli. In 1934, Mclndoo contested certain conclusions of 



Minnich with respect to blow-flies and claims that it is not 



necessary, in order to explain the proboscis response, to assume 



that the tarsi bear gustatory organs. He describes experiments 



Pyrameis atalanta, highly 

 magnified. t, trichogen ; 

 c, probable cap-cell ; s, 

 sensory cells ; t", tube of 

 chemoreceptor ; «, dark- 

 staining end of tube ; 

 p, papilla. (From 



Eltringham.) 



