JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 



t Jnnoary 27, 1670. 



jjn poU exposed to the open air, touched ; bnt many splendid 

 plants have been eaten over, and rendered useless, over which 

 mi old nosh was placed to screen them a little from the wet. 

 Even as respects Crocuses, of which mice are so fond, I have 

 ! '.u'l those ia tie open air but little injured, but the other 

 night mice chared some fine potsful just coming into bloom, 

 oatinK the flower-stems and buds, and then dealing out and 

 demolishing the roots. We suspect that in this case bdth 

 crasB and field mioe had been present, as our common garden 

 mouse does not often meddle with bulbs and corms after the 

 head has so far grown. After catching and destroying myriads, 

 we still have more than enough. In the frosty Eights they 

 would soon have made wrecks of young trees and shrubs, as 

 ,vo. but for washing them to the height of a foot 

 otihi with a mixture of soot, lime, and cow dung, thin enough 

 to be quickly applied with an old syringe. Mice are almost as 

 good at this work as a herd of deer, which will feed and grow 

 fat on the bark and the young wood of trees, and even, as in the 

 case of the Laurel, if the bark and the young wocd be bitter 

 and disagreeable. In such cases the more nursed and protected 

 the plants are by our kindness, the more likely will they be to 

 suffer from such attacks. 



There is, however, a sort of natural protection that often 

 helps to save young plants, if not always, at least generally, 

 from such depredators, also from the severity of frost — namely, 

 the protection of weeds. We can almost imagine a sagacious 

 mouse reasoning in this way — " Ah ! these can be of little 

 value, or the gardener would have given them more care and 

 attention." At any rate, among others I will mention two 

 facts. Some time ago I took up and potted some Collinsia 

 hicolor to secure early blooms from it, as thus treated it makes 

 a pretty early-flowering plant, and is good for cut flowers. 

 These plants in pots were put under the protection of a light, 

 and almost every plant is cut down to the surface of the pot. 

 Quite near them the same kind of plants, with a fair allowance 

 of weeds among them, without any protection, are untouched. 

 Near these are some healthy patches of young Lettuces, sown 

 late in autumn for early spring planting. A part had been 

 oleared of weeds, and the surface of the ground had been 

 stirred a little with a pointed stick. A part had been left to 

 themselves, the plants thickly showing the points of their 

 leaves through a carpetiug of Chickweed, &z. The first well- 

 cared-for lot suffered a little from the frost, but much more 

 from having the hearts nipped out by mice. The second un- 

 cared-for lot does not seem to have been touched or injured in 

 any way. Thus there may at times be an advantage in care- 

 lessness and slovenliness. But for the Chickweed and the car- 

 peting of snow I might have been induced in the sharpest 

 frost to have stuck a few green twigs among them as a little 

 protection. — E. F. 



OF THE LAWS OF SEX IN PLANTS. 



[The following paper was read by Mr. Thomas Meehan, 

 Editor of the (American) " Gardeners' Monthly," before the 

 American Association for the Advancement of Science.] 



In my paper on Adnation of Conifers (see vol. xvii., page 

 438), I believe I established the fact that the stronger and 

 more vigorous the axial or stem growth, the greater was the 

 cohesion of the leaves with the stem. By following the same 

 line of observation I have discovered some facts which seem 

 to me to afford strong probability that similar laws of vigour 

 and vitality govern the production of seeds in plants. 



If we examine Norway Spruces when they are in blossom in 

 the spting, we find the male flowers are only borne on the 

 weakest shoots. The female flowers, which ultimately become 

 cones, only appear on the most vigorous branches. As the 

 tree grows these strong shoots become weaker, by the growth 

 of others above them making it shadier, or by the" diversion of 

 food to other channels, and thus as these shoots become weaker, 

 we find them losing the power of producing female flowers; 

 and the law in this instance seems very clear that with a 

 weakened vitality covte.; an increased power to bear mate flowers, 

 and that Only in the best conditions of venetati re vigour are female 

 Howtn produced. 



be Arbor Vita?, the Juniper, the Pine— in fact all the different 

 genera of Conifers that I have been able to examine — exhibit 

 the fame phenomena ; but the Larch will afford a particularly 

 interesting illustration. When the shoots of the Larch have a 

 vigorous elongating power, the leaves cohere with the stem. 

 Only fcliaceous awns give the appearance of leaves. When 

 they lack vigour, lose the power of axial elongation, true leaves, 



without awns, appear in verticils, at the baso of what might 

 have been a shoot. Every one is familiar with these clusters 

 of true leaves on the Larch. In the matter of sex, an examina- 

 tion of the tree will show the following grades of vigour : — First, 

 a very vigorous growth on toward maturity, or the uge necessary 

 to commence the reproductive processes. The reproductive 

 age is less vigorous. Taking a branch about to bear flowers, 

 we find somewhat -vigorous 6ide branches, with the usual 

 foliaceous awns. The next year some of the buds along theso 

 side branches again branch, bat the evidently weaker buds 

 make only spurs with leaf verticils. As these processes go on 

 year after year the vertioirs become, of course, shaded by the 

 new growth, and get weaker in consequence, and thus, in the 

 third year, some of these verticils commence to produce female 

 flowers, or a few of the -very weakest may bear male ones. Bnt 

 only in the fourth or fifth year, when vitality in the spurs is 

 nearly exhausted, do male flowers appear in very great abun- 

 dance. Indeed, the production of male flowers is the expiring 

 effort of life in these Larch spurs. They bear male flowers 

 I and die. 



What is true of Coniferac seems also to exist in all monoecious 



plants. In the Amentacea- the male flowers appear at the first 



expansion cf the leaf buds in spring, as if they were partly 



I formed during the last flickerings of vegetative force the fall 



before, but a vigorous growth is necessary before the female 



flower appears. In Corylus, Carpinus, Quercus, Juglann, 



Alnus, and, I believe, all the common forms of this tribe, wo 



find the female flowers only at or near the apex, or first great 



I wave of spring growth, as if it were the culmination of vigour 



j which produced tbem, instead of the decline, as in the male. 



Some of these plants make Eeveral waves of growth a-yeor, eaeh 



successively declining in vigour, and thus the cones do not 



appear on the apex of the young shoot, but on the apex of the 



j first and strongest wave. This beautiful illustration of the 



I connection of vigour with the sexes can be seen particularly in 



! Pinus pungens, P. inops, P. mitis, P. rigida. and perhaps some 



others. 



In the Larch end White Spruce for instance, a second wave 

 will often start after the cone has commenced forming, and the 

 singular appearance is presented of a shoot growing out of the 

 apex of the cone. These varying waves can be seen in Cyper- 

 aceaj, sometimes placing the male and sometimes the female 

 at the apex of the culm, but always the female in the greatest 

 line of vigour. I do not know of any case where the sexes are 

 separate on the same plant, that extra vigour does not always 

 accompany the production of the female, and an evidently 

 weakened vitality the male parts. 



Mere vigour, however, will not always indicate the degree of 

 vitality. The Pinus Mugho seldom exceeds 10 feet high, and 

 its shoots are not nearly as vigorous as its near relative, Pinna 

 sylvestris ; and yet it commences its bearing age by a free and 

 vigorous production of female flowers. But power of endurance 

 is a high test of vitality, and an alpine farm should possess this 

 in a high degree. In its relation to sex this form cf vital force 

 will also have an interest. The -vitality of a tree is always 

 more or less injured by transplanting. Sometimes it is so 

 injured that it never pushes into leaf again. It always pushes 

 out later than if it had not been moved, and in proportion to 

 the injury to the vitality is the lateness of pushing. Clearly, 

 then, earliness of pushing forth leaves is a test of vigorous 

 vitality. Now, some Norway Spruces push forth earlier than 

 others. There is as much as two weeks' difference between 

 them, and it is remarkable that those which push out the 

 earliest — may we not say those which have the highest powers 

 of vitality ? — are most productive of female blossoms. Arbori- 

 culturists may make good use of this fact. Norway Spruces, 

 which have a drooping habit, are the cone-hearing forms. No 

 way has before been discovered to detect them until they get to 

 a bearing age. Now it will be seen, the earliest to push forth 

 in the spring will be cone-bearing or weeping trees. 



It is not so easy to see the influence of vigour or ether forms 

 of vitality, as affecting the sexes in hermaphrodite plants as in 

 monoecious cnes, yet here there are some remarkable facts of a 

 similar character. In some flowers the forces which govern 

 the male and female portion respectively seem nearly equally 

 balanced. Then we have a perfect hermaphrodite — one with 

 the stamens and pistils perfect, and one communicating its in- 

 fluences to the other — a self-fertilising flower. Irrmany species, 

 however, we notice a tendency to break up this balance. It 

 becomes either a pistillate or a staminate, either by the sup- 

 pression or greater development of one force or the other. If 

 the force is id the female direction it begins by requiring the 



