Nov. 



1883. 



* KNOWLEDGE • 



273 



CURIOSITIES OF THE SUB-TROPICAL 

 GARDEN. 



By Geo. G. Chisholm, M.A., B.Sc. 



FEW more welcome additions have been made in recent 

 years to the ornaments of our parks than those plants 

 •derived from suh-tropical regions which are now generally 

 to be seen in greater or less abundance during that part of 

 the year in which our climate permits of their flourishing. 

 These sub-tropical additions are not always more splendid 

 than the natives of our own islands or of other tem- 

 perate climes, but they at least add variety and nove!ty 

 to the aspect of our parks and gardens, and very frequently 

 they strike us by the marked contrast of their forms when 

 compared with those with which we are more familiar. 



But our observation of these strangers from warmer 

 latitudes is enriched with a deeper and wider interest 

 when we do not content ourselves with looking at what 

 any \'isitor may see from the walks, but take the trouble 

 to know something about what strikes our eye. What are 

 the uses, we may ask, of some handsome plant which we 

 cannot help admiring ? Where does it grow ? Is it of 

 any peculiar scientitic interest ? Has it any value in the 

 arts, or does it yield anything to commerce 1 It will, no 

 doubt, be worth while to answer a few such questions that 

 may be put, let us suppose, by a visitor to the sub-tropical 

 gardens of Battersea Park. 



In those gardens, as in any similar gardens, at the pre- 

 sent time there is one sub-tropical plant which is almost 

 sure to attract our notice among the very iJrst — the plant 

 known to botanists as Carina indica, and often popularly 

 termed Indian shot, from the appearance of its seeds. It 

 will be seen in large beds, which can be distinguished even 

 at a distance by the tall spikes of sometimes scarlet some- 

 times yellow flowers. On a nearer view one admires the 

 plant not only on account of its handsome flowers, hut 

 also for their beautiful foliage, their large, elliptical, glossy 

 leaves, with numerous parallel veins running on each side 

 from the midrib. 



From a scientific point of view, this plant is of no little 

 interest, by reason of the peculiar structure of its flower. 

 This flower has within the whorl of true petals another 

 whirl of petaloid organs, which, from their mode of de- 

 velopment, ixre shown to be modified stamens, or rather 

 stamens which have not developed into their normal form, 

 and have consequently remained barren. Within that 

 again another whorl is represented only by a single fully 

 developed organ, one-half of which at the top is in the 

 form of an anther, while the remainder is petaloid. Usually 

 this is stated to be a stamen, in which the fliament and one 

 anther cell have assumed a petaloid character, but it seems 

 to have been shown by Dr. Dickie that it is in reality a 

 stamen bearing a two-celled anther as usual, but united 

 along its whole length to another petaloid anther. 



On either \iew this flower is scientifically interesting as 

 pres<>nting an e.\ample of the assumption liy one part 

 •of a flower of the form proper to another. Such changes 

 are by no means uncommon in the vegetable world, and it 

 was phenomena of this kind that first drew attention to 

 the essential unity of type that characterises leaves, sepals, 

 petals, stamens, carpels, and otlier parts of a plant. It was 

 such phenomena to which Goethe pointed in his celebrated 

 little treatise on the INTetamorphoses of Plants, in which, it 

 may he mentioned, tho case of Carma is referred to. 



If we turn to another part of the garden we ma}- see 

 another plant, which is not indeed sub-tropical, but wliicli 

 is interesting because it illustrates tho same transition as 

 "Carma. Floating on the surface of the little lake which 



adorns the park, the blossoms of the white water-lily can 

 hardly escape the notice of any visitor, and in these 

 blossoms tlie passage from petal to stamen is shown in the 

 most unmistakable manner. The parts of the flower in 

 this case, are arranged in a spiral round the summit of the 

 axis, and the first appearance of a stamen is in the form of 

 a minute portion of an anther pinching the top of a petal. 

 Gradually as we pass inwards we find the antheriferous 

 portion becoming larger while the petaloid portion becomes 

 more and more narrowed, till at last in the inner turns of 

 the spiral we find the change complete. The petals have 

 got narrowed to the form of ordinary filaments which are 

 surmounted by long anthers. The flower has typical 

 petals and typical stamens, but it is impossible to say 

 where the petals and stamens begin. 



Let us look before leaving at another remarkable orna- 

 ment of the gardens. In this case it is a tree, and the 

 most striking thing about it is its large, pendulous, some- 

 what trumpet-shaped white blossoms, blossoms sometimes 

 reaching twelve inches in length, though not in this 

 country. This tree is one of those which are unfortu- 

 nately known even to men of science by more than one 

 name. Formerly it was called Datura arhorea, a name 

 still retained by many, and this name shows that it is a 

 close ally of the thorn apple {Datura stramonium), which 

 the old botanist Gerarde introduced into this country, 

 where it now grows wild in many parts. It difl'ers, how- 

 ever, from the thorn-apple not only in the arboreal habit to 

 which it owes its specific name, but also in wanting those 

 spines on the fruit which have earned for the British 

 Datura its popular designation, and likewise in having that 

 fruit only two-celled, whereas the Daturas proper have the 

 fruit more or less completely divided into four cells or 

 compartments. These ditt'erenoes have induced £ome 

 botanists to refer this tree to a separate genus, to which 

 they give the name of Brugmansia, which is again an 

 unfortunate circumstance, inasmuch as that same name is 

 applied by other botanists to another genus as different 

 from that of which we are speaking as any genus of 

 flowering plants could well be. Our Brugmansia, it should 

 be mentioned, is a member of the potato family, and like 

 the potato is a native of South America. 



Amoxcst other interesting cases recently recorded of the 

 good services rendered by the Westinghouse brake two in 

 particular may be mentioned. On the 11th ult. an express 

 train from Hull to Leeds, on the Xorth-Eastern Railway, 

 when running over fifty miles an hour was turned off" the 

 main line into a branch at Crossgates, near Leeds, by a 

 blundering signalman. The brake was at once applied, and 

 the train was coming to a stand, when in taking another 

 pair of points it was thrown off' the line, and separated 

 into two or three portions ; but, thanks to the automatic 

 nature of the brake, each was separately stopped and no one 

 was injured. The other case comes from the United States, 

 and happened on the Baltimore and Ohio Railway. The 

 Chicago TrihunK says : — "Yesterday morning at the dawn 

 of day, when the express, which is due in Chicago at 5. -10 

 a.m., was about thirty odd miles from the city, and running 

 at great speed, the engineer noticed smoke in front of him, 

 and feeling a presentiment of danger, instantly applied the 

 air brakes and stopped the train, loaded with its sleeping 

 freight, just in time to keep it from plunging into the Little 

 Calumet River. The bridge was Imrnt, and not over 30 ft 

 separated the locomotive of the train from the yawning 

 abyss." The simplicity claimed for certain brakes would 

 prove but a poor substitute for the quickness and certainty 

 of the automatic brake in such cases as the above. 



