36 



THE GARDENERS' MONTHLY 



[February, 



erarius in 1694, and Vaillant in 171 7, completed 

 ■Crew's observations, but the doctrine was not uni- 

 versally admitted till 1729, when Linnzeus pub- 

 lished his excellent treatise " De Nuptiis et Sexu 

 Plantarum et Sponsalia Plantanim. Kolreutcr, 

 1 761, was the first to suggest cross-fertilization, 

 through the agency of wind or of insects. Spren- 

 gel, in 1793, submitted that the fertilization of a' 

 hermaphrodite flower by its own pollen was the 

 exception. Andrew Knight, 1799, ad\ocated that 

 a plant would not continue fertile by its own pol- 

 len through many generations. Robert Brown 

 confirmed many of these \iews by observations on 

 Asclepiadacea; and Orchidaces. In 1862, Darwin 

 issued his work on the "Fertilization of Orchids^ 

 and the evidence he offered has been confirmed by 

 the observations of Hildebrand, Axell, Delpino, 

 MuUer, Lubbock. Slade, &c. Since then Haekel 

 and others have believed that the views of the 

 others claim more for the relations between color 

 and insects, than the facts warrant, but 'the subse- 

 quent observadons of M. Musset seem to indicate 

 that Haekel's views are unsound. — Abridged from 

 Revue de l' Horticulture Beige. 



Honey Dew.— We give place to the following 

 from a correspondent of the London Garden, in 

 order to call attention to a question we regard as 

 by no means settled : 



" Bee-keepers will rejoice greatly at what they 

 regard as honey-dew, the deposit of which is very 

 heavy this year, as aphis are more than usually 

 prevalent, the undersides of the leaves of limes, 

 sycamores, cherries, and most other trees, being 

 quite covered with them, and, as a natural conse- 

 quence, the foliage below is heavily coated with 

 their excreta, which they exude in such quantity as 

 to form a glutinous paste, and varnish the leaves 

 quite over. Many look on this so-called honey- 

 dew as a sort of distilled sweetness brought about 

 by atmospheric influence, and never dream of 

 aphis, or think it is the discharge from any insect, 

 else they would not be found, .as I have seen them, 

 licking the nectar off, and appearing to enjoy it, 

 till they knew from what source it came, when they 

 soon showed disgust, and a violent fit of expecto- 

 radng seized them. ♦ Hop-growers, and those con- 

 nected with gardening, know only too well what 

 honey-dew means, and when they see it are well 

 aware that the enemy is at work sucking the vital 

 energ'es out of the plants, and crippling their 

 growth. What is wanted now is a good down- 

 pour of rain to wash the foliage, and cleanse it of 

 both parasites and honey-dew ; for though the latter 

 may be good for the bees, qnd go far to\yards as- 

 sisting them to fill their hives with honey, it stops 

 the pores of the leaves, and prevents free respira- 

 tion, and thus interferes with their health." 



Now many of us have seen honeyed liquid ex- 

 creted from aphides, and are therefore quite ready 



to agree with the notion of the animal origin of 

 honey-dew as generally accepted. 



But the writer is quite sure he has seen numbers 

 of cases where trees have swarmed with aphides 

 without any honeyed surface to the leaves below 

 them, and on the other hand some few cases, espe- 

 cially on the linden, where no trace of any aphides 

 existed. Only last season he saw the whole brick 

 pavement beneath the shade of two American 

 plane trees in front of the Wills Hospital in Phila- 

 delphia, covered with stains from drops of liquid 

 which had fallen from the trees. Myriads of flies 

 were feasting on the sweetness wasted there. So 

 far as the eye could tell at that distance from the 

 ground, no aphides were visible. By the aid of a 

 sun umbrella handle, some of the lower leaves* 

 were gathered, but there were neither aphides be- 

 neath or any appearance of varnish on the upper 

 surface of these shaded leaves. Across the street 

 were other plane trees, the branches almost reach- 

 ing those on the other side, but no sweet liquid was 

 under these as in the other case. It is inconceiv- 

 able that trees so near together should swarm with 

 aphides in one case, and have none in the other. 

 These street trees were left with regret that they 

 were not growing nearer where some close atten- 

 tion might be given towards unraveling the mys- 

 tery. It seems, howe\er, inconceivable that even 

 though aphides should have been in extraordinary 

 numbers on the tops of these trees, they should be 

 able to excrete enough honey, not only to cover 

 the myriads of leaves with a gloss below them, but 

 have still some to spare to splash the brick side- 

 walk as with a hose. Though we have to give 

 some sort of an assent to the aphid origin of 

 honey-dew, we cannot help feeling there is some- 

 thing back of it all not yet explained. — Ed. G. M. 



Th?: L.\cqukr Tree of J.a.pan. — The precise tree 

 which produces the gum used to make the peculiar 

 lacquer work of Japan, is now ascertained to be 

 from the Stagmaria verniciflua, a tree genus closely 

 allied to the Rhus or poison vine family. There 

 are vast plantations of the tree in Japan. Each 

 tree is tapped, and during four months juice enough 

 to fill a three-ounce bottle exudes. One thousand 

 trees yield about 12,000 gallons. It is said that 

 the exact manner of its preparation has not yet 

 been discovered by Europeans. 



M1GRATION.S OF Birds. — An Illinois friend says: 

 " I take great interest in everything touching the 

 habits of small birds. I have no doubt the food 

 question has much to do with their migrations. The 

 robins left us very early last fall, owing to the fruit 

 and late berry crop being a failure." 



