34 



Garden and Forest. 



[January 15, 1890. 



and without vigor when transplanted. The product from such 

 a beginning will be late, small and of inferior quality. This is 

 not an imaginary case. I have seen seed from the same stock 

 give the best satisfaction, and in other cases none at all. The 

 sole reason for these opposite results was that in one instance 

 the seed was sown properly, and improperly in others. I 

 have more than once noted experiences of precisely this 

 character among the growers of Cauliflower in Suffolk County. 



Floral Park, L. I. " C. L. Allen. 



Tuberous-rooted Begonias. — Now is the time to sow seed of 

 tuberous Begonias for bedding, or for making showy pot 

 plants this season. Sow in pans in, or rather on (for the seed 

 needs no covering), a mixture of sifted leaf-soil and peat, using 

 the siftings to cover the drainage. Set the pans in saucers, 

 where there must be sufficient water to keep the surface moist 

 by absorption. Place pieces of glass over them, tilted to admit 

 air, rather for protection against careless watering and syring- 

 ing than for the purpose of keeping them "close." Sixty de- 

 grees, night temperature, is sufficient for germination. Grad- 

 ually remove the glass as the seedlings develop, and prick 

 them out when large enough to handle in soil containing some 

 loam. Increase the quantity of loam at successive stages, and 

 give some shade in the middle of the day as the sun attains 

 power. Plant out in June. A shady situation is generally 

 recommended, but there is a difference of opinion. Save 

 your own seed. In doing this you will succeed best with pot 

 plants. 



Wellesley, Mass. F. D. H. 



Correspondence. 

 The Forest-floor. 



To the Editor of Garden and Forest : 



Sir. — While I appreciate and subscribe to the main idea of 

 the editorial in Garden and Forest for December 18th, allow 

 me to call your attention to an expression which may event- 

 ually give trouble to those who wish to convince others of the 

 influence of forests on waterflow. 



You refer to the spongy condition of the forest-floor, and it 

 is quite an accepted theory that the forest-floor " acts like a 

 sponge, taking up large quantities of water and gradually giv- 

 ing it up to the soil." Even scientific men are apt to use this 

 simile. Now, this is not the action of a sponge, as a simple 

 experiment could prove. While some forest-floors — by no 

 means the majority — do act like a sponge, they are by that 

 very action depriving soil and springs of a considerable share 

 of water. 



It is curious that the simile has been used so frequently 

 without an attempt by somebody to first study the action of a 

 sponge. It is simply this : after the sponge is saturated with 

 water, and not before, it will give out water below if more 

 water is added above — that is to say, if the water in the sponge 

 is driven out by pressure of more water. As soon as the sup- 

 ply from above stops, the sponge will stop giving out water 

 from below, except so far as it contains more water than it 

 has capacity to hold. After that, the movement of the water 

 is upward, not downward. Evaporation begins, the upper 

 parts become dry and supply themselves with water from the 

 lower strata by capillary action. Thus, while a spongy floor 

 would do the one thing claimed for it — namely, "retain the 

 water in the spongy mass " and diminish the water which runs 

 off — it would not do the other thing which is implied, namely, 

 furnish gradual supplies of water. This it could possibly do 

 only if the underlying soil strata had become dry earlier than 

 the spongy cover, which is the case only rarely and under 

 exceptional conditions. 



The question, then, is, how far does the forest-cover re- 

 semble a sponge ? Fortunately for water supplies in springs, 

 the resemblance occurs more rarely than the general use of 

 the simile implies. A sponge is a material with remarkable 

 powers of capillarity, as can be seen when placed in a puddle 

 of water, which it will drink up with avidity. Such capillarity 

 in a minor degree may be found in some moss covers, and 

 the consequence is that the amount of water held and after- 

 ward evaporated — but not given up to the soil — is quite aston- 

 ishing. The quantity of water thus retained may amount to 

 from seventy to eighty per cent, of its weight, so that if the 

 moss-cover exceeds a depth of four or five inches it may with- 

 hold nearly all the water from the soil, except of heavy rain- 

 falls and snows, and this water is lost by evaporation twice to 

 three times as fast as from other litter ; whether an additional 

 amount of water and how much of it will run off superficially 

 or be filtered into the soil, depends largely upon the nature of 

 the latter. 



The various kinds of litter, which, after all, form the greater 

 part of forest floors, appear and act, indeed, quite differently 

 from sponges ; their capillarity, as can be inferred to some 

 extent from their rate of evaporation, is only small, and they 

 will filter through to the soil much larger amounts of water 

 than the moss (thirty to forty per cent. more). This kind of 

 soil cover, like the moss, does also require a considerable 

 amount of moisture to saturate it, but less than the moss- 

 cover ; it loses less by evaporation and gives up more water 

 to the soil. 



Altogether, we will have to admit that the forest-floor not 

 only retards the run-off, but it diminishes the amount of water 

 which percolates into the soil. And yet it acts beneficially 

 upon the steady flow of springs by checking evaporation — the 

 greatest dissipator of water supplies. Regularity of flow in 

 the springs, brooks and rivers, as far as it depends upon forest- 

 cover, is due to reduced evaporation under the protection of 

 forest-shade and forest-floor. 



The mechanical retardation of the run-off, which the irregu- 

 larities of the forest-floor and the trunks, stumps and undei'- 

 brush produce, will certainly tend to reduce the height of 

 freshets in brooks by distributing the flow of water masses 

 over a longer time. But it would be an unwarranted, easily 

 demolished generalization, to say that this retarding influence 

 is everywhere useful in preventing floods of rivers. It may, 

 on the contrary, prove the very source of danger — geological, 

 geographical and topographical conditions being most potent 

 in altering the value of this influence. 



It would lengthen this communication too far to argue the 

 influence of forests on floods in general ; my purpose is sim- 

 ply to object to the popular idea that a forest-floor acts like a 

 sponge, and to insist that even the admitted retarding influ- 

 ence of the same may not in all cases and everywhere be a 

 benefit. 

 Washington. B. E Fernow. 



Mr. Eyerman's Orchids. 

 To the Editor of Garden and Forest : 



Sir. — During the past three years Mr. Eyerman, of Easton, 

 Pennsylvania, has been making a collection of Orchids which 

 now fill three houses, and a large conservatory has recently 

 been added, containing a fine collection of Palms, Ferns, 

 Cycads, etc., among which Orchids in bloom are tastefully ar- 

 ranged. In this structure I noticed on a recent visit scores of 

 Lalia autiimnalis, and its showy variety, Atrorubens, there 

 being no fewer than fifty spikes crowded with blossoms. L. 

 albida was equally well flowered, most of the plants being on 

 blocks, and bearing unusually strong spikes of well formed 

 and very large flowers. Lalia Gouldia?ia, a very scarce plant, 

 was well represented here by a spike carrying several of its 

 rich purple blossoms, and here, too, were many examples of 

 the charming scarlet-flowered Sophronites grandiflora. Some 

 fine Cypripediums of the Insigne type, flowering for the first 

 time, were very interesting, many of them being distinct in 

 character, and among them was a splendidly grown plant of 

 C. Leeanum superbum, with twin-flowered spikes, and flowers 

 of great size and exceptionally bright color. Here, too, was a 

 good example of Vanda cosnilea carrying a dozen of its lovely 

 blue flowers, and near by Oncidium tigrinum, with well 

 branched stems laden with rich yellow and chocolate blossoms. 



In the house devoted to the Cattleyas and Laslias many 

 choice plants were promising flower. C. Triana and many of 

 its varieties will soon make a fine display, as will the scarce 

 C. Lawreticeana, well grown specimens of which were fur- 

 nished with strong flower-sheaths. C. Percivaliana was rep- 

 resented by several large plants, and among the Lselias were 

 quantities of finely flowered L. anceps, and its white variety, 

 L. anceps stella, carrying three well developed spikes. This 

 variety has hitherto proved somewhat difficult to manage, but 

 Mr. Msenner, the gardener here, has been very successful 

 with it. The plants in baskets are well exposed to the light, 

 and during their growing period receive a liberal supply of 

 water with an abundance of air. In this house the pretty 

 AngrcECum Sanderianum was seen, and some enormous spikes 

 of the yellow-flowering OfiCidium Cavendis hiamtm were rap- 

 idly pushing for bloom. A fine variety of O. Forbesii was 

 very conspicuous, its chocolate and golden-yellow flowers 

 growing in quantity on a well branched stem. Fine examples 

 of Odontoglossum Harryanum and Comparettia Macroplectron, 

 with its rosy pink flowers, were in excellent health, and at each 

 end of the house were two handsome specimens of Cym- 

 bidium Loivianum almost ready to bloom. 



In the Cypripedium house, among the rarer varieties, were 

 noticed a grand specimen of C. calurum and C. grande was 

 in superb health, together with C. meirax, C. plunerum, C. 



