210 



KNOWLEDGE, 



[September 1, 1894. 



attempt it. It is now to be seen stuffed at the Museum of 

 Science and Art, Edinburgh. I shall presently describe 

 the great strength of this bird. 



Among other characteristics, penguins are distinguished 

 by having the bones of the fore-arm flattened, and by a 

 very broad shoulder-blade. The wing feathers are very 

 short and are not differentiated into quills. The young 

 are hatched in a helpless condition. In many respects 

 they resemble, and they are probably related to, the puffins 

 and the auks of the Arctic Ocean. 



Although penguins are quite imable to fly, one must not 

 look upon their fore limbs as feeble and useless members. 

 They are indeed highly specialized for swimming and 

 crawling, and occasionally also they are used as powerful 

 weapons of defence, as anyone who has seen the effects of 

 a blow which an emperor penguin can give will easily 

 recognize. During the recent expedition, as already 

 stated, we succeeded in capturing and bringing on board 

 alive a very fine emperor penguin ; he stood on deck, 

 clothed in silken robes of white and black, decked with 

 gold and purple, a very monarch among his many admirers. 

 An almost full-grown retriever pup that belonged to one of 

 the seamen disapproved of his presence and pounced upon 

 him from behind ; the bird seemed to deem his assailant 

 of little importance, as he only turned his head round and 

 drove the dog off with his beak. A second time the dog 

 approached the penguin at his side, and with such force 

 did the bird strike the dog on its head with his flipper, 

 that he sent it away howling with its tail between its legs. 

 It was with the utmost difiiculty that five of us secured 

 this penguin, on account of its great strength ; it required 

 a man to each leg, a man to each flipper, and a man to 

 his head and neck in order to hold him down. He even 

 broke loose after being strongly bound. The muscles of 

 its breast weighed more than one-third the total weight 

 of the bird, and all this mass of muscle is used to 

 force the wing downwards and forwards. If the reader 

 will look at the keel of the breast-bone of the emperor 

 penguin in the British Museum, he will find that it does 

 not compare meanly with that of the golden eagle and the 

 swan, both powerful birds of flight, while its coracoids are 

 very much more strongly developed. Now this keel serves 

 for the attachment of the muscles of the breast, and is, 

 therefore, an indicator of the relative strength of the fore 

 limbs of different kinds of birds. Although all penguins 

 are not as large as the emperor penguin, they are all equally 

 powerful in proportion to their size. I have seen the 

 smaller kinds jump out of the water on to a cake of pack 

 ice, the surface of which was fully three feet above the 

 surface of the water. Curiously enough, they do not take 

 the advantage of distance, but approach quite close and 

 rise almost vertically out of the water, neatly settling on 

 their hind limbs in an erect position. This is accomplished 

 by the propelling power of their fore limbs. 



TYPES OF FLORAL STRUCTURE.-IL 



By the Eev. Alex. S. Wilson, M.A., B.Sc. 

 {Continued from page 164.) 



THE natural order to which a flower belongs can 

 sometimes be approximately ascertained from the 

 number and position of its parts alone ; thus, if we 

 find a specimen with five petals and five stamens 

 placed opposite them we need have almost no 

 hesitation in concluding that it belongs to Primulaceffi. 

 The sea-pink is almost the only native flower outside the 

 primrose order, at all common, which possesses a penta- 



merous corolla and antipetalous stamens. The order 

 Cruciferre is easily known ; its flowers have a four-petaled, 

 cruciform corolla and six stamens, two of the latter being 

 shorter than the others. Compositse, Labiatse, Umbelli- 

 ferre, and a few other orders may likewise be recognized 

 by head-mark. To determine the systematic position of a 

 flower, a number of characters must, however, as a rule, 

 be taken into account. We require to know what whorls 

 are present, of how many parts each is composed, and 

 whether the whorls are alternate or superposed. The 

 cohesion or degree of union existmg among the members 

 of the same whorl must be observed ; also whether or not 

 all the parts in any whorl resemble each other, the flower 

 being regular or actinomorphic where they are alike, and 

 irregular or zygomorphic if the parts are dissimilar. The 

 placentation, or mode in which the ovules are disposed 

 within the ovary, is another character of primary impor- 

 tance in identifying plants. The different whorls of a 

 flower may be quite separate and independent of each 

 other, or they may adhere ; the degree of adhesion is of the 

 greatest use in classification. This last-mentioned character 

 is ascei'tained from a vertical section of the flower, and is 

 not therefore shown in the floral diagram, since this is 

 merely a representation of what one sees on looking down 

 into the blossom — a ground plan in fact, into which one or 

 two particulars from the cross section are introduced. 

 For the present we shall confine our attention to those 

 characters which admit of representation by means of a 

 floral diagram, leaving aside meantime, for the sake of 

 simplicity, adhesion and other characters which are only 

 visible in a vertical section. 



Orchis. 



Cypripedium. 



Grass. 



Canna. 



Floral diagrams, as will be readily understood, greatly 

 assist the memory in retaining the general characters of 

 the various natural orders, and are therefore most helpful 

 to the beginner in botany ; but besides this, they often 

 bring out in a most instructive way the affinities of 

 different groups. As an illustration of this we may take 

 the Orchidaceffi, an order in which the flowers assume the 

 most irregular, diversified, and fantastic shapes ; they 

 have little or no resemblance to the simple, regular, and 

 symmetrical blossoms of the lily order, to which, however, 

 they are very closely related. The Liliaceae, which pro- 

 bably represent a very early monocotyledonous type, have 

 six stamens, while Oirhis has but one ; genera allied to 

 the latter, however, exhibit every gradation, from the 

 hexandrous to the monandrous conditions. The single 

 perfect stamen of orchis is homologous, with the anterior 



