102 



SCIENCE-GOSSIP. 



on each side, prothorax sharper at sides. The 

 abdominal extremity is slightly more truncated, 

 and the caudal points are shorter than in the fore- 

 going species. Occurs not uncommonly in ponds 

 and marshy waters of Great Britain and Ireland. 



The nymph of Oxygastra curtisii is, unfortu- 

 nately, unknown. The only known localities in 

 the world for the occurrence of the imago, are the 

 New Forest, and a few others in the South of 

 England ; also Portugal, and the South of France. 

 Ponds in well-wooded places are the most likely 

 lurking-spots for the nymph. 



The three foregoing Corduliines occupy a 

 singular and interesting position, inasmuch as 5. 

 metallica and C. cenea axe direct migrants, whilst 

 0. curtisii is an excellent example of a tropical 

 form enduring in a country which has undergone a 

 vast change from the heat of the carboniferous 

 period to a period of sub-arctic cold. 



Now follow the nymphs of the family vEschnidae, 

 sub-family Gomphinas. Those of the division 

 Gomphina may easily be known by their antennas of 

 but four joints. 



LINDENIA forcipata has only been taken here 

 in the imago form once. Its nymphal characters 

 are : head, heart-shaped ; mask, one-fourth longer 

 than broad ; middle third, a rounded lobe with 

 teeth and a comb of flat scales ; spines at 

 sides of segments two to nine (not three to nine, as 

 in Gomphus), but merely rudiments of dorsal hooks; 

 the triangular caudae are sharp, and slightly longer 

 than final body-segment. Dr. Hagen's characters 

 for Lindenia nymphae do not apply to L. (Onycho- 

 gomphus) forcipata. 



GOMPHUS vulgatissimus is somewhat like a 

 mole-cricket, with the legs similarly formed for 

 burrowing in mud. The abdomen is flat, without 

 dorsal hooks, but with spines at the sides of 

 segments six to nine. In the female the abdomen 

 is slightly broader than in the male, and at the end 

 of the eighth ventral segment is a small bifid 

 tubercle. The front tarsi are all two-jointed, the 

 hinder pair three-jointed. This larva, at first 

 greyish, turns green as it matures. It is scarce, 

 and confined to the Southern Marshes. 



CORDU LEG ASTER annulatus is a synthetic 

 form, allying the true Gomphina with the JEschnina. 

 The nymph has conical eyes. The antennae are 

 seven-jointed, as in the iEschninae. The mask is, 

 as in Libellulina, spoon-shaped ; it extends be- 

 yond the middle pair of legs, and covers the mouth 

 and upper lip. The abdomen is almost cylindrical, 

 and tapers towards the tip ; the anal appendages 

 are pyramidal, and rather long ; the tarsi are all 

 three-jointed. This species inhabits swiftly flowing 

 streams, and is generally distributed but local. 

 ( To be continued. ) 



[Erratum. — On page 81, line 37, second column, read 

 " abdominal " for " lamellar."] 



RISKS IN INCUBATION. 



By David J. Rice. 



A MORAL has oft times been pointed and a tale 

 adorned by writers on the evil attaching to 

 bird-nesting. Although in no sense an advocate 

 for the wholesale robbery and destruction of eggs, 

 I should like to point out how much more destructive 

 is nature herself, comparably with collectors and 

 schoolboys. 



I have carefully observed a number of nests in 

 a small area, chosen so that the chances of human 

 interference were of small degree. The nests were 

 all found on one day, and visited seven days after- 

 wards with the following results : — 



(1) Nest of bullfinch (Pyrrhula europcea), built on 

 the lower branches of a fir-tree, containing 

 one egg. On revisiting, found the egg broken 

 and nest deserted. 



(2) Nest of chaffinch (Fringilla ccelebs), built close 

 against an oak-tree, seven feet from the ground, 

 ready for eggs. On revisiting, found three eggs 

 broken in the nest. 



(3) Nest of hedge-sparrow (Accentor modnlaris), in 

 a small holly shrub growing up in a haw- 

 thorn hedge ; two eggs. On revisiting, three 

 eggs broken in nest. 



(4) Nest of song-thrush (Turdits musicus), in a 

 clump of furze and bramble, three feet from 

 ground; three eggs. On revisiting, four eggs 

 broken in the nest. 



(5) Nest of chaffinch (Fringilla ccelebs), in a holly- 

 tree ; three eggs. On revisiting, the eggs 

 broken in the nest. 



(6) Nest of song-thrush (Turdus musicus), in a 

 hawthorn hedge ; four eggs, hard sat. On re- 

 visiting, young birds four days old, dead in the 

 nest, and being rapidly eaten by ants. 



(7) Nest of chaffinch (Fringilla ccelebs), in a 

 beechen hedge ; five young ones newly hatched. 

 On revisiting, young birds dead— two in the 

 nest, the remaining three beneath it. 



(S) Nest of great-titmouse (Pants major), built in 

 an old jay's nest in a holly-tree ; two eggs. On 

 revisiting, found the eggs still there, but the 

 nest was deserted. 



The last three, cases were undoubtedly the 

 result of heavy rains, that of the titmouse being 

 only natural from its unusual position, the nest 

 being open to the sky, and consequently quite 

 unprotected. The other nests were normal in 

 position, and the broken eggs were, I should say, 

 the work of jays and like birds, squirrels, and 

 possibly mice and rats. A heavy storm in the 

 middle of the breeding season does more harm in 

 a few hours than all the schoolboys in any year. 

 It would be of interest to the readers of Science- 

 Gossip if students of bird-life in their various 

 districts would pay some attention to this question 

 of the mortality of young bird-life and its causes. 

 These notes are the result of somewhat general 

 observation, and will, I hope, be followed by a 

 more special enquiry. 



7, John Street, Bedford Row, London, W.C. 



