144 



KNOWLEDGE & SCIENTIFIC NEWS. 



[July, 1904. 



caterpillars. Although the caterpillar is alive when 

 infection takes place, it slowlj- dies, and its body be- 

 comes filled with a dense mass of myccliiini, from which 

 one or more simple or branched, cl<)n4,'-aled Iruiting- 

 bodies spring at a later period. 



One very beautiful fungus belonging to this section is 

 not at all uncommon in this country-, it is called Cordy- 

 (cps militaris, and is generally found growing up 

 amongst moss in damp places in woods. It is club- 

 sh.iped, one to three inches high, and of an orange-red 

 colour. If the stem is carefully followed down, it will 

 be found to spring from the pupa of some moth or 

 butterfly. 



At the present time the knowledge that certain fungi 

 attack and destroy insects has been turned to practical 

 account. Fungi attacking insects injurious to crops, as 

 locusts, cockchafers, <.tc., are cultivated on a large scale 

 for the purpose of .securing quantities of spores. These 

 spores are preserved in small sealed glass tubes until 

 required. When an army of locusts appears the con- 

 tents of one or more tubes are mixed with water and 

 placed on bread or some other substance eaten by the 

 locusts. The spores thus eaten germinate quickly in 

 the bodies of the insects, and death soon follows. Now 

 a^ it is the custom among locusts tO' eat their dead 

 friends, the infection spreads at a great rate. By such 

 means large areas have been cleared of destructive 

 locust swarms in -South .Africa and elsewhere. 



Before the discovery of lucifer matches, a large hoof- 

 shaped fungus {Polyporus fomentarius), growing on the 

 trunks of trees, was used throughout Northern Europe 

 for making amadou or tinder. The thick, brown woody 

 flesh of the same fungus, cut intO' slices and beaten until 

 it assumes the appearance of felt, is used at the present 

 day in Germany for the manufacture of chest protec- 

 tors, caps, purses, bedroom slippers, and various other 

 articles. .V good assortment of such, along with ex- 

 amples of the fungus and the felt, are exltibited in the 

 Cryptogamic room, No. 2 Museum, Kew Gardens, 

 where many other interesting forms of fungi are also 

 on view. 



The fact that Lichens differ from other plants in being 

 partly fungal and partly algal, the two collectively con- 

 stituting the plant, is well known. This condition of 

 things is called symbiosis, vmtualism, or commensalism ; 

 \\ hich means tliat each benefits respectively by the par- 

 ticular kind of work done by its neighbour, the total 

 result of such mutualism being that Lichens can grow 

 luxuriantly in IfKalities where neither fungi nor alga?, 

 as independent plants, could flourish. It is important to 

 understand clearly the difference between a parasitic and 

 a symbiotic fungus. TTie former is always injurious, 

 without txjnefiting in any way the plant it is parasitic 

 upon. The symbiotic fungus benefits, without in anv 

 u ay injuring, the plant it is associated with. 



.Symbiosis between fungi and other plants has of late 

 years been shown to be much more general than \\as 

 suspected. In many forest trees, as spruce, larch, 

 silver fir, oak, beech, hazel, A-c, the fine rootlets that 

 supply the plants with food are entirely surrounded by a 

 dense weft of fungus mycelium, which acts on the 

 humus in which the plant is growing, in other words, 

 converts the humus into food tli.-it can be absorbed bv 

 the r(x>t of the tree from the fungus surrounding it. 

 The fungus and the rootlet it surrounds is called a 

 mycorhiza. 



Heaths, orchids, ferns, and all flowering plants not 

 possessing chlorophyll possess mycorhiza, on which the 

 l.-.st named are entirely dependent for their food supply. 



FoLStirvg AnimoLls. 



Bv R. Lydekker. 



The fact that a large number of species of mammals 

 and other animals undergo more or less prolonged and 

 continuous fasts during the period of their winter or 

 summer sleep is familiar to us all. .A.nd although un- 

 doubtedly remarkable, the phenomenon is not such as 

 to excite any great wonder or surprise in our minds ; 

 for during the periods of such slumbers the more active 

 functions of the body are to a great extent suspended, 

 while those that are carried on act slowly and entail 

 comparatively little waste of tissue and energy. More- 

 o\ er, before the period of the winter torpor or hiberna- 

 tion takes place, many of these animals, such as bears, 

 accumulate large stores of fat on various parts of the 

 bixly, which suffices to supply all the waste entailed by 

 the respirators' function during the period in question. 

 Fat is also accumulated by certain species, such as the 

 mouse-lemurs of Madagascar, previous tO' the summer 

 sleep, or aestivation, and is used up in a similar manner ; 

 such summer sleeps being, it should be noted, under- 

 taken for the purpose of avoiding the season of great 

 heat and drought, when food is difficult or impossible to 

 prixrure. Other species, on the contrarv, like squirrels, 

 dormice, and hamsters, lay up supplies of food in their 

 winter c|uarters, on which they feed during waking 

 inter\-als in the torpor, sO' that the fast is by nO' means 

 so prolonged or so continuous as in the case of the first 

 group. There are, however, yet other animals, such 

 as bats, among mammals, frogs and toads among 

 amphibians, and the We.st African lung-fish among 

 fishes, which apparently neither put on fat nor lay up a 

 store of food during their period of torpor ; which in 

 the case of all of them is unusually prolonged. Bats, for 

 instance, generally remain torpid throughout the winter 

 months ; while the .A.frican lung-fish passes the whole of 

 the dry season comfortably curled up within a nest 

 formed bv the caked and dried mud of the river bed. 

 In all these latter cases the fast must accordingly be 

 prolonged and of a severe type. 



Nevertheless, whether partial or continuous — whether 

 mitigated by a store of fat or food or not — all such fasts, 

 as already said, take place when the chief functions of 

 the bodv are more or less completelv in abeyance. 



In marked contrast to the above is the case of cer- 

 tain members of two widely sundered groups of 

 animals, which undergo a protracted voluntary fast 

 during the breeding season, when the bodily functions 

 are in their highest activity, and there is a strain on the 

 whole system which is unknown at other times. How 

 the creatures manage tO' exist at all under such circum- 

 stances is little short of a mar\-el ; nevertheless, not 

 only doi they exist, but for the greater portion of the 

 time they are in the very pink of condition, and it is 

 only when the breeding season is over that they fall 

 away and require a period of rest and good feeding in 

 which to recruit their energies. 



The creatures in question are the sea-lions and sea- 

 bears on the one hand, and the salmon on the other. 



The fact that the adult males of sea-lions and sea- 

 bears, which constitute the family of eared seals, or 

 Otariidce, fast while on shore w-ith their " harems " 

 during the breeding season has been known for a long 

 time ; but it is onlv recentlv naturalists have satisfied 

 themselves that the salmon abstains from food, almost, 



