2J.6 



KNOWLEDGE. 



[No-\-EMBER, 1903. 



Of the three leafless saprophytic kiuds, the Bird's-nest 

 Orchis, Neotlia Nidus-avis, is easily knowQ by the pale 

 brown colour of its stem and flower-spike, resembling 

 the dead beech-leaves among which it loves to grow. It 

 is a comparatively large plant, attaining a foot or more in 

 height. In general appearance it is very like the parasitic 

 Broom-rapes (Orohanche), but the flower has all the 

 characteristic features of the Orchid. The Coral-root 

 {Coralhrrhiza innata) sends up from its curious branching 

 root-stock a slender greenish stem devoid of leaves (though 

 bearing a few sheaths) which terminates in a lax spike of 

 small whitish flowers. This is a rare Scottish plant, 

 growing in boggy woods. The third saprophyte, Epipogum 

 aphi/Uum, is a pale yellow leafless plant with flowers 

 variegated with pink. In Great Britain its inclusion in the 

 flora rests on a single station discovered many years a^o 

 in Herefordshire, where it has not been seen since. 



Of the three remaining Orchids, Liparis Locselii, the Fen 

 Orchis, now nearly extinct, has a pair of comjiaratively 

 large basal leaves, and a spike of a few small whitish 

 flowers. Next we have the tiny Bog Orchis {Malaxis 

 ■paiudoaa) already referred to, a little fleshy yellowish 

 plant, found in clumjjs of Sphagnum on bogs here and 

 there throughout the British Islands. Lastly, a very 

 different plant claims our attention — the beautiful Lady's- 

 slipper, Cypripedium Calceolus. This plant differs materially 

 in structure from all other British Orchids; it has two 

 stamens instead of one, and the whole flower is constructed 

 on a different model, the labellum being very large and 

 pouch-shaped. In our only British species the large and 

 beautiful flower is maroon, with a yellow labellum. It is 

 a very rare North of England plant, now probably extinct. 



Eeviewing generally the distribution of our Orchids, we 

 find that they are on the whole a lowland lime-loving 

 group. Only a little over a dozen species out of over forty 

 have a thoroughly wide distribution ; most of the others 

 have their headquarters in the south and east of England, 

 where the chalk prevails, whence some, such as the 

 Pyramidal Orchis, Bee Orchis, and Autumnal Lady's- 

 tresses, spread outwards for a considerable distance ; others, 

 like the Red Helleborine and Orchis simia and militaris, 

 being confined to one or two stations within that area. A 

 few {Liparis, Spiranihes xstivalis, and Mala.ris) are bog 

 plants, all but the last being of very restricted English 

 range. Sabenaria albida and Listera cordata haunt the 

 uplands. Two species, the Creeping Lady's-tresses and the 

 Coral-root, are northern, and with us confined to Scotland. 

 The lovely Lady's-slipper has, or had, its home in the 

 North of England. 



Lastly, we have two particularly interesting outlying 

 species, found in the British area in Ireland alone — 

 Hahenaria intacta and Spiraiithes Bomanzoffiana. These 

 at once arrest the attention of the student of geographical 

 botany as representing the two extremes of our flora — the 

 furthest limits from which the elements which compose 

 our present vegetation have been drawn. H. intacta is a 

 characteristic Mediterranean species, inhabitmg Spain and 

 Portugal, southern France, Italy, Dalmatia, and Greece. 

 A wide stretch of sea and land separates it in its Irish 

 home from its next present habitat. It is probably a very 

 early inhabitant of Ireland, which in old days crept 

 northward along a former European shore-line which has 

 now long disappeared below the waves. Here, on the 

 warm limestones of the almost frostless west of Ireland, it 

 still survives in quantity. The other Ii-ish Orchid, 

 Sitiranthes Bomanzoffiana, has a very different origin, but 

 a similar tale to tell. This is a sub-Arctic ])lant, with its 

 headquarters in Canada and the northern United States. 

 It has crept across Behring Sea into Kanitschatka, but 

 elsewhere in the Old World it is known only in Ireland. 



To account for its presence here, we must assume that land 

 formerly occupied part of the area now covered by the 

 North Atlantic Ocean. Perhaps by way of Greenland 

 and Iceland the plant may have migrated eastward ; 

 possibly the lonely peak of Rockall, or the Porcupine 

 liank, represents the ^\Teck of its former home. But here, 

 cut off by thousands of miles of sea from its nearest 

 settlement, it grows still, a living monument of the changes 

 that earth has seen even since our present flora began to 

 colonize the land. 



CONSIDERATIONS ON THE PLANET MARS. 



By E. M. Antoniadi, f.e a.s. 



It is now more than a quarter of a centiu-y since 

 Schiaparelli called attention to the " canal '' s}'stem of 

 Mars, and, during this time, thought has been active in 

 framing theories to accoimt for the new facts revealed by 

 observation. So long as the term " canal " was agnosti- 

 cally applied to streaks which united to one another the 

 so-called " seas " of the planet, there could be scarcely any 

 improvement on its choice, and no objection to its use. 

 But when the Milan observer spoke of the "robust dikes " 

 and " inundations " of these " canals," the care of opening 

 whose locks would have been committed to the Martian- 

 Secretary of State for Agriculture himself, a distinct shade 

 was cast on the seriousness of the term in question. 



Two years had not elap.sed after the discovery of the 

 " canals " before the late Mr. Green urged the objection 

 that some of them were nothing else than the edges of 

 faint half-tones ; and that, in such markings, it was 

 diftieult to recognise the earthly attributes of water 

 channels. But this far-reachiug remark of the gifted 

 English observer was soon cast into oblivion before the 

 afiparently weightier evidence of Schiaparelli's observa- 

 tions, which, for many years, seemed to carry everything 

 before them. It was gradually realised, however, that to 

 assume the fidl objective reality of the Milan residts 

 implied such a startling state of things on our ruddy 

 neighbour, that it was no longer safe to follow Schiaparelli's 

 interpretations to the letter. But no one ever thought of 

 challenging the veracity of the various telesco]>ic impressions 

 disclosed by the laborious watches of the great Italian 

 astronomer. Slowly and patiently those results have 

 been exhaustively confii'med by the ablest followers of 

 Schiaparelli, and are now jwrmanently acquired to science. 



We are indebted to the abnormal peculiarities of the 

 " canals " for that seasonable reaction. Their sudden 

 shifts of position, leaps, disappearances, reappearances, 

 intensifications and duplications, marked out the 

 "canals" as rather the inconstant vagaries of physiological 

 phenomena than as the permanent features of a cooling 

 world. All Martian energy must necessarily have its 

 source in the sun, since the presence of polar snow-caps 

 shows us the surface of the planet to derive so small a 

 quantity of heat from the interior as never to enable it 

 to attain, unassisted, the freezing point of water, or 

 perhaps even of carbon dioxide. The elegant cosmogonieal 

 speculations as to the youth of Mars are thus completely 

 outweighed by this more credible observational testimony. 



The question of the objectivity, or of the subjectivity 

 of the "cauals" has frequently been examined, and often 

 decided one way or the other. A careless observer would, 

 in fact, deem it more reasonable to consider the " canals " 

 either as wholly imaginary, or as wholly real, than as a 

 mixture of both reality and illusion. He could speciously 

 argue that there must be one single cause for the canal 

 impression ; and that, by tracing the latter to a variety of 

 sourceSjOur reasoning becomes unphilosophical, and betrays 



