June 22, i8S8.] 



SCIENTIFIC NEWS. 



589 



was laid by a "Plymouth Rock," on May 22nd. The 

 two parts are joined by a stout band at the ends, and in 

 one is the yolk entire and in the other the white. This 

 specimen is to be seen at No. 71, Regina Road, N. 



Weapons of Insects. — Dr. Lampert gives in Humboldt 

 a summary of the means employed by insects in re- 

 pelling their enemies. Interesting facts have been 

 elicited concerning the stings and hairs, the latter of 

 which are so common among lepidopterous larvae, and 

 which often exert an injurious action upon the human 

 skin. Many of the hairs have barbs ; some, especially 

 the smaller, bore perpendicularly with their fine points 

 into the skin, and are driven deeper by any pressure or 

 contact applied above. At the same time a chemical 

 irritant adhering to the hairs contributes to the inflam- 

 mation of the injured part. The excretion of a hquid 

 product is very common as a protective. The "cuckoo- 

 spit," in which the larvae of Aplirophora spuinaria is con- 

 cealed, is well known. It is curious that this secretion in 

 different countries is ascribed to the cuckoo. In other 

 cases we notice the emission of a secretion in case of 

 need, generally a corrosive or offensive liquid. Every 

 collector of insects knows the secretions of the Carabs, of 

 Meloe, of Coccinella, of Cychrus, and of the puss-moth. 

 Nor must we overlook the characteristic odours of the 

 goat-moth, caterpillar, or of the larva o? Lina popiili. The 

 latter is very economical, for as soon as the danger is 

 over it draws back into its body the whitish, intensely 

 smelling drop which oozes from every tubercle. The 

 power of the Brachiiii, bombardier beetles, to project a 

 blue vapour against an enemy is well known. In Cerap- 

 tcrits ^-iiiacnlaliis, a member of the exotic Paiissidae, this 

 vapour is found to contain free iodine (see Tijdschrift d. 

 Nedcrl. Dierkiiiid Vercenigiiig, 2 ser., Decl. i, 1887, 106- 

 loS). In cases where we see insects shunned by insect- 

 feeders, though no protective agent is known, they have 

 probably a disagreeable taste. Seitz mentions that 

 butterflies are distinctly shunned by birds. 



Insect Pests. — We have already mentioned the 

 plague of caterpillars now experienced in, and near 

 Epping Forest, and extending to Hadley and Highgate 

 Woods, and other localities where oaks abound. The 

 chief offenders are the caterpillars of Hybernia defoliaria 

 and of Chiniatobia brumata. The former species, known 

 to some English collectors as the " Mottled Umber," 

 may now be seen dangling from the branches of the oaks 

 literally in myriads. The second species, the "Winter 

 Moth," is less given to dangling, but it spins two or three 

 leaves together with silk. It attacks most kinds of 

 fruit-trees, apples, pears, and plums, and does not dis- 

 dain standard roses. As regards the enemies of these 

 depredators, the starlings and tom-tits seem the most 

 active. Upon sparrows we place no reliance, knowing 

 that they eat caterpillars only in default of something 

 more to their taste. Ichneumons seem this season not 

 very plentiful, but good service is being done by the 

 carnivorous caterpillar of Cosmid irapczina, sometimes 

 known as the " Dun-bar." This caterpillar is found on 

 the oak and the horn-beam, and may to some extent 

 feed on the leaves, but it evidently prefers animal food. 

 In chasing and capturing other caterpillars it shows 

 an address and pertinacity which speak of hereditary 

 predaceous habits, 



THE AUSTRALIAN MAMMALS. 



THERE must be few zoologists who have not been 

 greatly struck by the very singular manner in which 

 so many of the Australian mammals reproduce, as it were, 

 various characteristics of those which not only inhabit 

 other continents, but which also belong to totally 

 different orders. All the indigenous mammals of 

 Australia are marsupials ; that is, the female animals 

 are furnished with a peculiar pouch, formed by a fold in 

 the skin, in which they carry their young for a consider- 

 able time after birth, and in the walls of which the teats 

 are situated. This structure is necessitated by the fact 

 that these young, in many cases, are born while little 

 more than mere embryos (the kangaroo itself is only an 

 inch long at birth), so that protection during the early 

 stages of their growth is absolutely essential, while at 

 the same time they must be almost continuously 

 nourished by their mother's milk. Hence they are 

 placed in the marsupial pouch as soon as they'enter the 

 world, and there they remain, it may be, for six or 

 eight months, leaving it occasionally for a short time 

 towards the end of that period, but always returning to 

 it when danger threatens or hunger assails. And this 

 structure it is which forms the distinguishing feature 

 of the group. 



Of the three animals which do not appear to possess 

 it, and which are yet found in a wild state on the 

 Australian continent, one — the dingo — has almost cer- 

 tainly been introduced from elsewhere, while the porcu- 

 pine ant-eater and the duckbill are now admitted to 

 constitute a " sub-order," traces of the marsupial 

 structure being distinguishable when carefully looked 

 for. In all others it is conspicuous enough, although 

 not in every case sufficiently developed to serve as a 

 receptacle for the young. 



With the sole exception of the opossums, which are 

 natives of the New World, these marsupial animals are 

 strictly confined to Australia and the neighbouring 

 islands. No marsupials are found in other parts of the 

 world ; no mammals belonging to other parts of the 

 world are found in Australia. This, the smallest of the 

 continents, has neither monkeys, bats, carnivora, insec- 

 tivora, rodents, nor ungulates. Pachyderms are un- 

 known ; edentates do not exist. And yet representatives, 

 so to speak, of most of these groups are found among 

 the marsupials themselves, feeble imitations, as it were, 

 of stronger species belonging to the higher divisions, so 

 that the marsupial order forms a sort of epitome of Old 

 and New World mammals upon a reduced scale, the re- 

 semblances being so perfect that they cannot be over- 

 looked, while the presence of the characteristic pouch 

 debars us from referring any of the animals in question 

 to the families to which otherwise they appear to belong. 

 Thus we have the dogs represented by the Tasmanian 

 wolf, in which the peculiarities of teeth, limbs, and form 

 distinguishing theCanida; are faithfully reproduced ; the 

 bears by the Koala, or Australian bear; the squirrels by 

 the Petaurists ; the edentates by the Echidna : and so 

 on. And, more remarkable still, in the Wellington 

 caves of New South Wales the fossil bones of a mar- 

 supial lion have been found, and are now to be seen in 

 the museum belonging to the Mines Department of 

 Sydney. These bones, which consist principally of 

 teeth and jaw-bones, were submitted to Professor Owen 

 for examination before being sent for exhibition ; and, 

 according to his report, their owner was of true leonine 



