15^ DR. K. W. DAMMERMAN, oN IIVHRIDS 



as larva in the wood, during the whole dry season, to appear 

 as beetle at the setting in of the western monsoon. 



The offspring is also rather numerous, of the above mentioned 

 Batocera' s often more than 200 larvae might be got from 

 one female ; onl)-, the breeding of such a large number of 

 larvae of considerable size, — they reach a length up to 

 10 cM. — , requires a large quantité' of newl)xut Ficus-vvood. 



For ever)' four or five larvae a piece of wood of i M. length 

 and of an arm's or leg's thickness is required, if one wants 

 to be certain that the larvae will develop into beetles. If 

 one rears too many larvae in a piece of wood of limited 

 length, the larger larvae will devour the smaller ones. 



For the crossings individuals reared b}^ myself were selected ; 

 of these the parents as well as the grandparents were known 

 and which showed no deviations from the normal t)'pe. 



As 'Caç.gigas generally become much bigger than albof asciata, 

 small individuals were selected for them, which in size agreed 

 with albo/asciata, in order to prevent that difference in size 

 might be a hindrance to the cross-breeding. 



The crosses succeeded ver}- well, only the numbei of 

 hybrids was very small, viz. 14 from the cross albo/asciata 

 d X g'igas $ and 1 5 from gigas S X albofasciata Ç. 



This small number of offspring, like the smaller size of the 

 individuals and the occasional bad development, is probably 

 onh' parth' a consecjuence of hybridisation. Parti}' it is owing 

 to insufficient feeding, as the larvae had to be reared on sawed- 

 off Ficus-wood, which after some time desiccates of course. 



At the cross albofasciata (S X ^'g^^^ $ the eggs were laid 

 between April 4 and Jul}' 20 191 3, the beetles hatched between 

 October 19 1913 and January 28 1914. 



At the reciprocal cross the eggs were laid between November 

 17 1913 and Januar}' 14 1914 and the beetles hatched between 

 March 26 and August 7 1914. 



The hybrids show the following pecularities (See pi, 1 3 and 14): 



The}' rather differ between themselves, as well as regards 

 colour as design, on the whole the colour is intermediate, 

 neither the pure brown of the gigas nor the pure grey of 

 the albofasciata ; as regards design the h}^brids are strongly 

 matrocline, so the\' are most like the mother. 



