ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 59 



cocoons, and nests. Some observations of former writers are ques- 

 tioned. Thus he has been " unable to confirm the statement that 

 Pentatoma griseum watches over her young like a hen over her chickens 

 or that the favourite prey of Reduvkis personatus is the bed-bug " ; nor 

 does he regard the superficial resemblance between Volucella and a wasp 

 as having anything to do with mimicry. " The relation of Volucella to 

 the wasp seems to be that of a simple scavenger." 



In regard to limitation of instinct, it is noted that when the nest of 

 the common wasp is covered with a bell glass, "the enclosed wasps 

 never dig a passage out, but remain cooped up till they die ; and 

 though stragglers left outside will dig their way in, they are equally 

 unable to show their companions the way out or even to make their own 

 escape." 



Viviparous Insects.* — N. Holmgren has examined a very large 

 number of species in which viviparity occurs, and finds that in rela- 

 tion to this condition the structure of the female organs is variously 

 affected in different cases. In those cases where parthenogenesis occurs 

 the development of the egg may take place within the ovary, as in 

 the Aphides and Coccidao, or in the body cavity as in Miastor larvae. 

 In amphigenetic types the place of storing of the eggs depends upon the 

 region in which fertilisation is effected. In the Diptera they are retained 

 in the vagina or its differentiations, in Strepsiptera in the body cavity or 

 brood canal, and in Orina and Chrysomela in the canals of the ovary. 

 In Diptera there is sometimes differentiated on the vagina a diverticulum 

 which acts as a brood-sac, in others the vagina is lengthened and 

 functions as a brood-sac, while in others only the wider and more 

 anterior portion so functions. 



In Diptera the larvae may remain only till partially developed ; 

 in pupiparous forms the young are born in a highly advanced state. 



In most viviparous insects there is no special maternal provision 

 for the brood. Only in pupipara are there specific organs of nutrition, 

 the accessory glands being transformed into nutritive glands, a fact 

 which is related to the long life of the brood in the vagina. 



Variations in Lycffinidse.j— L. G. Courvoisier describes variations 

 from the normal type of wing-marking in various Lycsenids. especially 

 Lycccna and Chrijsopltanus. They are not irregular, but follow 

 certain lines, some with too much (" luxuriant " forms), others with too 

 little (impoverished forms) of certain normal characters. The author's 

 observations were made before he became aquainted with Oberthur's 

 great work, 'La Variation chez les Lepidopteres ' (18%). 



Red and Yellow Pigment of Vanessa. \ — Dr. M. Grafin von 

 Linden has investigated the chemical nature, function and origin of 

 these pigments. The various colours of the butterfly are the result of 

 various stages of oxidation of a pigment that is itself attributable to- 

 the plant-cells forming the food of the caterpillar. 



* Zool. Jahrb., six. (1903) Heft. iv. pp. 431-68. 



t MT. £ckweiz. Entomol. Ges., xi. (li)03) pp. 1S-25 (1 pi.). 



I Biol. CViitralbl., xxiii. (1903) pp. b21-8. 



