E. UlNDI.K 200 



(KXMirring wht'ii individualH an* krpt cniiiimuilly on tlu* UmIv, iindcT 

 which iMiulitioiiH iws many Jts !>'7 tlaily havt- Ihmii nronltMl. 



Ill my ox|K'rimont..s {hv (vi\\n\o nirrly laid iin»r«» than SO i*^^ all told, 

 an«l in many vxim^h mnsidtTahly fowrr. so that the cunditiofiM imiMt Im« 

 n'ganli'<l jis having bt'i'n somewhat unfavourahlr. 



Tho larvao usually hat^'hrd iVom thf c^^s aftrr 10 nr II <liiys, and 

 niuuIUHl thnv tinu's Ih'Auh' hriMimin^ ;ulult. Thr ti?st nmult ^mi'mlly 

 tKXMirnMl aft*T (» days, an<l the two t'olloNvin^^ rach afl^T 5 days, s<» that tin- 

 U»Uil drvclopmont from tiixt sta^c larva to adult usually t<M)k ahout 

 16 days. Thoiv wa,s a ciTtNain amount <»l" mortality amongst the larval 

 stJi^i's, JUS simwn in the rrcM»nls on pj). 270-271, wluro ihr nundur of 

 larvae emerging is shown in each case. 



When feiniing such a lari^e mnuher **( lice it- wsis sometimes necessary 

 t<» plact* tw»» or three hnMnls on the arm at the sjime time, hut when- 

 ever jH>ssible thi'v wen' fe<l successively, in order to avoi<l the |K»ssil)ility 

 of their y^ettin^ mixi'd. In one or two instances, h(»wever, it is pmhable 

 that indiviiluals have wandered frtun nne hnnxl to another, as shown 

 by the counts of the larvae before an<l afti-r fe('^lin;^^ In all these causes 

 the expi'riment is marked with a «pier\'. 



ImuRHliately an adult appeared it was isolated, ami it us<'d for 

 furthiT ex|K'riments w;is crossed with one of the (►pposite sex as soon 

 as possible. For practical reasons the adults could not be kept alive 

 until all the members of the brood had completed their development, 

 and in consequence some of the crosses had to be made with material 

 that Wiis available rather than that which one would have selected. 

 In view of the onerous task of feeding, all adults not intended for 

 further experiments were killed an(l preserved, in order to keep down 

 the numbers to a minimum. 



The reconis of these experiments are summarised in the fV>llowing 

 table, in which is shown ( 1 ) the number of the family, e.r/. /^8 or Z 15 ; 

 (2) the nature of the female parent, e.g. ex ^l 8 signifies that the female 

 came from the brood of family ^4 3 ; (8) the nature of the male parent 

 similarly expressed ; (4) the total number of larvae that hatched ; and 

 (5) the number of each kind of sex among the adults which reached 

 maturity. 



In some instances the same male, or the Siime female, was used for 

 more than one exi)eriment, and these are indicated by footnotes. 



