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SCIENTIFIC NKWS. 



[June 8, iSSS. 



tender to shift for himself and find his own food. Hatched 

 out thus early, the young and tender larvae must develop 

 temporary swimming organs and means of protection 

 which are quite useless to the adult. The first necessity 

 with them is to disperse, and they are provided with 

 simple but effective locomotive organs, which they dis- 

 card afterwards when they give up vagrant habits and 

 begin to feed in earnest. But there is no end to a good 

 natural history problem. So, having attempted to show 

 that metamorphosis depends upon the number of embryos 

 and the poor provision for their support, we must next 

 consider why a marine animal brings forth a family of 

 such uncommon numbers. The answer is that it has so 

 many enemies, and that vast numbers are needed to meet 

 the losses due to the voracity of the countless predatory 

 forms which people the sea. Fresh waters have their 

 pirates too, but the sea is far more thickly sown with 

 dangers. Lest the reader's patience should be altogether 

 worn out, we will stop explaining, and make no attempt 

 to justify or discuss this last statement. 



About eleven o'clock on Sunday forenoon the steamer 

 left Douglas for Port Erin, and the work done on that 

 day was sufficient to make up for a bad week, instead of 

 a bad day. The first cast of the dredge was made be- 

 tween Port Soderick and Port St. Mary in about i8 

 fathoms of water, where a fierce tide was running. 

 When the dredge came up it was full to the top with 

 dead and living shells of Pectitncuhis and all kinds of 

 univalves and bivalves, dead and alive, and a great mass 

 of beautiful Mclobesia, thati ittle understood calcareous, 

 coral-like seaweed. This particular bed of the lime-plant 

 was of a wonderfully rich colour, and the organic parts 

 of the plant v/ere almost invisible to the naked eye, even 

 when a fracture was made, so that it looked like a perfect 

 little tree coral. Besides this, there were countless forms 

 of life, many of them exceedingly interesting in their ap- 

 pearance and their movements. The hermit crabs were 

 plentiful in their shell-houses, and many kinds of star-fish 

 and Echini also came up. The common star-fish (Asterias 

 rubcits) appeared to flourish in the same spot, for some of 

 the specimens were quite iS inches across. The ascidians 

 were very plentiful, especially the odd-looking Botrylloides 

 rubnmi, and the polyzoans were very abundant. A few 

 casts of the dredge in the quiet water under the lee of 

 the Calf brought up, amongst other things, rare star- 

 fishes, like Cribdla rosea, Porania pulvillus, and Luidia 

 fragillissima. The real results of the expedition will 

 only be seen some months after this ; but the superficial 

 results of the one day's dredging were simply astonishing. 

 Between nine and ten o'clock Captain Young got all 

 the electric lamps read}', and the great white glare on 

 deck surprised the quiet dwellers in the Port, who knew 

 not what manner of men had come to visit them on a 

 Sunday night. When the party was all assembled, an 

 incandescent iamp was fastened inside a fine muslin 

 tow-net, and lowered down into the clear waters of the 

 bay. At a depth of five fathoms the pale white light 

 presented a most singular appearance, and illuminated 

 the bottom in a very ghostly manner. Another tow-net 

 and another lamp v.'ere lowered on the opposite side, 

 but kept near the surface, so as to see what difference 

 there would be between the living things on top and 

 those at the bottom. The effect of the white gleam of 

 electric lighthouses on sea birds is well known, for the 

 birds fly to their death against the tall sea towers ; but 

 the effect on fish is not so well known as it should be. 

 The salmon fishers in Highland rivers use the torch to 



attract the fish, which are then speared ; and it is found 

 that sea fish are also attracted by a flame, but they will 

 not bite at a hook, being dazed by the illumination. 

 There is a large probability that the electric light could 

 be profitably used for net fishing, and there is room for 

 careful investigation on this point, in connection with the 

 ever-pressing question of the " harvest of the sea." 



The results on Sunday night were surprising. The 

 surface net was found to be rich with small creatures 

 known as Copepods, along with the tiny larvae of 

 different fishes, while the deep-water net was swarming 

 with Amphipods, almost as large as house flies or ■ 

 ordinary beetles. These small relatives of the shrimp 

 and the lobster are intensely interesting to the micro- 

 scopist, and the electric light brought multitudes of them 

 to the tow nets. The gorgeous little crystalHne speck 

 (Anomalocera patersoni) was in great abundance, as 

 were the white-bodied, scarlet-eyed Ampelisca, and the 

 more aberrant Cumacea. 



Report of Observations of Injurious Insects and Common 

 Farm Pests, during tite year 1887, with Mctliods of 

 Prevention and Remedy. Eleventh Report. By 

 Eleanor A. Ormerod, F.R. Met. Soc., F.E.S., etc. 

 London : Simpkin, Marshall and Co. 

 Miss Ormerod, the consulting entomologist to the Royal 

 Agricultural Society, is well known as a zealous and 

 accurate student of the life-histories and modes of action 

 of our insect pests. In the report before us she com- 

 municates the results of the past year, some of which 

 are decidedly satisfactory, as proving that a close 

 examination of these minute enemies is the only way for 

 their repression. The season of 1887, with its unusual 

 atmospheric dryness, and with its hot days, generally 

 followed by chilly nights, seems to have been favourable 

 to various kinds of pests. 



One very interesting case is that of" clover sickness,' 

 caused by the minute eelworm (Tylenchus dcvastatrix). 

 This tiny vermin attacks not merely clover, but oats, 

 onions, etc. If cattle are fed on clover thus infected, the 

 Tylenchi passing unhurt through their digestive organs 

 may thus reappear in any crop dressed with their 

 manure. 



The Hessian fly (Cecidomyia destructor') was first dis- 

 tinctly recognised in Britain in iS85, and it extended 

 last year over a considerable tract, both in England and 

 Scotland, and has done considerable damage to barley, 

 but less to wheat. They have been favoured by the dry 

 weather, and it may be hoped that they will not multiply 

 rapidly if we have our usual amount of rain-fall. 



An unfortunate circumstance is that most of the 

 puparia (the cases in which the insect undergoes its 

 final transformation) are placed so low in the stems of 

 the grain that they remain in the field after reaping. 

 But if the Hessian fly is undoubtedly present in our 

 midst, it has come attended by its enemies — certain 

 minute four-winged flies — which prey on its larva or 

 pupa. 



Miss Ormerod proposes that the screenings from in- 

 fected grain after threshing should be burnt, and that the 

 stubble left on the field should be burnt also. It is also 

 advisable to sow the wheat as late as possible, so that 

 there may be nothing for the flies to lay their eggs on. 

 The Ribbon-footed Corn-fly {Chlorops taeniopit^) is no 



