1 86 BIRDS 



28. Two Guillemots 



to show as great a difference in marking as possible. 



29. Guillemot and Great Auk 



to show similarity in shape and marking, hut 

 difference in size. 



30. Nightingale and Kingfisher 



to show a very dark egg and a very light one. 



31. Sparrow Hawk and Cuckoo 



to show difference in size and shape. 



32. Lapwing and Ring Dove 



to show a tapered egg and a roundish egg. 



33. Cuckoo and Skylark 



to show similarity in shape, size, and marking. 



34. Cuckoo and Hedge Sparrow 



to show dissimilarity of shape and marking. 



35. Cuckoo and Meadow Pipit 



to show similarity of colour, shape, and size, 



36. Crow and Rook 



to show similarity. 



37. Jackdaw and Magpie 



to show difference in size and markings. 



38. All the Tits 



39. Barn Owl and Tawny Owl 



to show difference in shape, namely, a pointed and a 

 round egg. 



40. Goldcrest and Mute Swan 



to show smallest and largest British birds^ eggs. 



41. Chiff Chaff and Willow Wren 



to show difference in markings. 



42. Great Tit and Nuthatch 



to show similarity. 



43. Kingfisher and Woodpecker 



to show white roundish eggs laid in dark places, 



44. Blackbird and Ring Ouzel 



to show similarity. 



45. English Partridge and French Partridge 



to show difference in size and markings. 



