January 31, 1913] 



SCIENCE 



181 



no desire to escape unless she is severely 

 molested and is quite content with her brood, 

 anxiously incubating it day and night." This 

 is the way Wagner, who is beset with a ter- 

 rible anxiety lest he commit this deadly sin 

 of " grober Anthropomorphismus," describes 

 the behavior of the same insect : " Eine nieht 

 weniger auffallende Erscheinung ist der Ver- 

 such der Hummel, das Nest auszubessern. 

 Erregt durch das eindringende Licht, steigt 

 sie von der Wabe auf den Boden herab und 

 kriecht riickwarts zu derselben zurlick, wobei 

 sie die bei solchen Gelegenheiten iiblichen 

 Bewegungen des ' Zusaromenscharrens ' trock- 

 ener Pflanzenteile ausfiihrt, d. h. nicht nur 

 Bewegungen macht, deren Bedeutung sie 

 nicht versteht, sondern nicht einmal im 

 stande ist, auch nur die geringsten Eesultate 

 ihrer Tiitigkeit wahrzunehmen, welche sie nur 

 aus dem Grunde ausiibt, weil diese Tatigkeit 

 eine Eeaktion auf die Gesamtheit der aus- 

 seren Eeize darstellt." Surely, if we may ask 

 Sladen how he Imows that the humble-bee ex- 

 periences anything akin to the affection and 

 solicitude of the human mother for her off- 

 spring, we may also ask Wagner how he knows 

 that such a highly organized insect as the 

 humble-bee is a mere machine and absolutely 

 unable to appreciate the results of any of her 

 activities. Such quotations reveal the differ- 

 ence between Sladen's and Wagner's methods 

 of observation and incidentally between the 

 two schools of animal behavior which they 

 represent. To one the insect is a wonderful 

 and inexhaustible living organism, whose 

 activities can be most satisfactorily described 

 in the language which we employ when speak- 

 ing of another individual of our own species; 

 to the other the insect is a pure mechanism, 

 whose every movement is easily expounded by 

 the observer, who stands in the foreground 

 and uses the observed object largely as a 

 means of displaying his own analytical and 

 explanatory acumen. The student of animal 

 behavior, who wishes to appreciate the merits 

 and defects of each of these methods, can 

 hardly do better than to read in close sequence 

 Sladen's and Wagner's memoirs on the 

 humble-bee. 



Sladen's book begins with a brief introduc- 

 tory chapter on humble-bees in general, their 

 geographical distribution, their relations to 

 flowers and their more important external 

 characters. This is followed by a beautiful 

 account of the life-history of the British spe- 

 cies, with excellent figures of their nests, illus- 

 trating the behavior of the queen in establish- 

 ing the colony, and the growth and arrange- 

 ment of the brood-comb and of the honey- and 

 pollen-pots. The author's interesting and 

 original classification of the British Bomhi as 

 '' poUen-storers " (B. lapidarius, terrestris, lu- 

 corum, soroensis, pratorum, jonellus, lappon- 

 icus and cullumanus) and '" pocket-makers," 

 which are subdivided into " pollen-primers " 

 (-B. ruderatus, hortorum, latreiellellus and dis- 

 tinguendus) and " carder-bees " (B. desham- 

 ellus, sylvarum, agrorum, helferanus and mus- 

 corum) is described and illustrated in detail. 

 The third chapter, devoted to the " usurper 

 bees " of the genus Psithyrus, carries us well 

 beyond the researches of Hoffer and gives us 

 the complete life-history of these extraordinary 

 parasites. As ascertained by Sladen, this life 

 history resembles in the most striking and sug- 

 gestive manner that of certain parasitic ants 

 of the genera Polyergus and Bothriomyrmex, 

 since the female Psithyrus usurps the position 

 of the Bomhus queen by killing her and 

 securing adoption by her workers, which then 

 assist the parasite in bringing up her brood. 



The fourth chapter takes up the other Bom- 

 hus parasites and enemies. These constitute 

 a very large and motley assemblage of 

 organisms, including the meadow mice, a pe- 

 culiar wax-moth (Aphomia sociella) which 

 devours not only the cells, but also the brood 

 of the humble-bee, a Tachinid fly {Brachy- 

 coma devia), the highly mimetic Volucella 

 tomhylans, besides several other Diptera be- 

 longing to the genera Pannia, Phora, Conops, 

 etc., several Hymenoptera, especially Mutilla 

 europcea, certain Braconids and ants, more 

 than 50 species of Coleoptera, among which 

 Antherophagus nigricornis, a small beetle that 

 is carried from the flowers, into the nests at- 

 tached by its mandibles to the proboscis of the 

 bee, is one of the most interesting, several 



