90 THE VICTORIAN NATURALIST. 



figure of ^. cochlearis. The only figure of A. stipitata available 

 was of the lorica only, which agreed in general outline and 

 number of spines, but differed in the arrangement of the tesselated 

 markings. Among other life noted were a number of very young 

 forms of Lepidurus. It was felt that these springs would well 

 repay the trouble of an occasional visit at different seasons of the 

 year, and the members present were indebted to Mr. C. French 

 for his thoughtfulness in including these pools in his route, and 

 also for his interesting explanation of the scale insects and 

 other plant parasites met with on the way." — C. French, F.L.S. 



ON A SPECIES OF ISARIA. 



By H. T. Tisdall, F.L.S. 



(Read before the Field Naturalists' Club of Victoria, i oth July, 



1893.; 

 We are all aware that animals for the most part prey on the 

 vegetable world, and on its destruction and subsequent absorption 

 animals live and thrive ; but it is not so well known that some 

 species of the vegetable world return the compliment. 



A number of fungi are entirely dependent for existence on the 

 nourishment which they obtain from the animal creation. Amongst 

 these parasites those that prey on various kinds of insects are not 

 the least curious. 



The three best known groups of these plants are Entomoph- 

 thorese, Laboulbeniacese, and Cordyceps. The Entomophthorese 

 form a species of innate absorption moulds — they absorb and re- 

 place theinternal organs of the insect, and only appearon the surface 

 when they have killed their hosts. These fungi are very minute. 

 The most common and familiar example will be found on the 

 dead flies on the window pane. White bundles may be observed 

 exuding from different parts of the body of the fly ; these are, in 

 the first instance, produced from a cylindrical germ cell, which 

 continuously grows in an apical direction, finally developing into 

 a branched body of cylindrical thread-like form, termed a hypha. 

 These hypbge, when first developed in the insect, are of different 

 sizes and shapes, constantly increasing in number by budding 

 until the body of the insect is almost completely filled by them. 

 If the insect be now exposed during moist weather, long threads 

 are produced from the hyphal bodies ; these protrude through the 

 joints of the insect, and either appear as simple white hairs or 

 become fruitful, the tips of the branches swelling and producing 

 gonidia. When the swollen ends are quite mature the mother 

 cell is ruptured, and the conidium or spore is forcibly ejected to 

 a considerable distance. The hyphje have accomplished their 

 work of destruction before they appear on the surface of the fly. 

 Mr. Gray gives the following graphic description : — " All these 



