No. 485] NOTES AND LITERATURE 



333 



Because of the rapid early decline in the rate of development 

 Professor Minot believes that the age of college entrance should be 

 lowered, and that professional studies should be entered upon at a 

 younger age. A final publication of these researches, which have 

 extended through many years, is in preparation. 



F, T. L. 



The Hypothesis of Mimicry.— Dr. Franz Werner of the University 

 of Vienna is a skeptical critic of the Mimikrylehre which he regards 

 as due to a rather crude anthropomorphic point of view (Biol. Cen- 

 tralhl, 27, pp. 174-185). He considers first the non-poisonous 

 snakes which are supposed to have acquired a protective resem- 

 blance to the poisonous forms of other genera inhabiting the same 

 locality. Since no snake-eating animal is known which makes a dis- 

 tinction between poisonous and non-poisonous forms, the latter can- 

 not be protected by the similarity of pattern. ^Moreover in some cases 

 there is reason to believe that the non-poisonous snake is the older 

 type: and that the venomous Elaps or Vipcra is the "imitator." The 

 stingless insects which deceptively resemble bees and wasps fare no 

 better than the harmless snakes, for stinging forms arc "not in tin- 

 least protected from their natural enemies; they fall a prey to many 

 birds as well as to lizards, frogs, toads, and spiders." Finn is cited 

 in evidence that the poisonous Danais is as eagerly devoured in India 

 by lizards of the genus Calotes as are its mimics. Poisonous forms 

 which often exhibit bright warning colors "to signaUze their unpalata- 

 bility to enemies in good season" are not secure. 



The similar patterns and colors of various snakes in a given locality 

 may be due to similar climatic conditions and food supply, the pig- 

 ments involved being physiological by-products. Color photography 

 is invoked to account for the correspondence in color l)(>twecn an 

 animal and its habitat. A physiolopcal rather than a tclcoloirical 

 explanation is desired. In otiicr words, it is believed that >iiiiihir 

 causes produce both the forms wlucli nunnc and thoM' which are 

 imitated, and that there is no other rehition hetwcvn ih(> two. Krom 

 the reports of field observers the number of in-tanco of eti'ciivc 

 mimicry has been so reduced that "as good as nothin>: remains.'" 

 Dr. Werner believes that man alone has been seriously deceived. 



