ESTIMATION OF THE HEAT NECESSARY TO GROWTH. 



559 



ai^kl together the daily maxima of sun-temperatures from tlie first of January 

 until the event in question takes place. 



A selection of constants obtained in this way from observations extending over 

 many yeara in Central Germany (Giessen) may be suitably inserted here. 



Constants fob the Issue of the Foliage-leaves from the Buds. 



Gooseberry {Ilibes Grossularia) 478°. 

 Hazel (Cori/lm AveUana) lOUl". 

 Beech {Fugus tUcatica) 1439°. 



Plane {Plalanus acerifolia) 1503°, 

 Walnut (Juglana regia) 1584°. 



Constants for the Opening of the First Flowers. 



Hazel {Corylna AveUana) 226°. 



Mezereou (Daphne Mezereum) 303°. 



Snowdrop {fialantkus nivalis) 311°. 



Sweet Violet ( Viola odorata) 576°. 



Cornel (Cornus mas) 576°. 



Apricot {Prunxis Armeniaca) 843°. 



Corydalis (Corydalis cava) 863°. 



Violet Willow {Halix Daphnoides) 968°. 



<Jowslip (Primula verig) 968°. 



Norway Maple (Acer platanoides) 1100°. 



Peach (Persica vulgaris) 1100°. 



Gooseberry (Itibes Grossularia) 1138°. 



Almond (Amygdalxu communis) 1196°. 



Gean (Prunus avium) 1265°. 



Sloe (Prunus spinosa) 1265°. 



Pear (Pirus communis) 1304°. 



Bird Cherry (Prunus Padus) 1325°. 



Apple (Pirus Jfalus) 1423=. 



Plum (Prunus domestica) 1423°. 



Alpine Woodbine (Lonicera alpigena) 1458°. 



Oak (Quercxu pedunculata) 1556°. 



Lil.ic (Hyringa vulgaris) 1556°. 



Walnut (Juglans regia) 1584°. 



Barberry (Berberis vulgaris) 1615°. 



Poet's Narcissus (Narcissus poeticus) 1615°. 



Hawthorn (Crat<xgus Oxyacantlia) 1649°. 



Lily of the Valley (Convallaria majalis) 1649". 



Horse Chestnut (.Esculus Hippocastanum) 1708°, 



Peony (Pceonia officinalis) 1818°. 



Laburnuui (Cytisus Lahurnum) 1818°. 



Mountain Ash (Sorhus aucuparia) 1844°. 



Norway Spruce (Abies excelsa) 1904°. 



Plane (Plaianus acerifolia) 2115°. 



Elder (Sambucus nigra) 2313°. 



Deadly Nightshade (Atropa Belladonna) 2346°. 



Acacia (Robinia Pseudacacia) 2404°. 



Scotch Pine (Pintis syh^estris) 2404°. 



White Water Lily (Xymphaa alba) 2506°. 



Ai-nica montana 2538°. 



Tulip Tree (Liriodendron tulipifera) 2538°. 



Rosa centifolia 2538°. 



Fox-glove (Digitalis purpurea) 2640°. 



Carthusian Pink(i>iani;Aj« Carthusianorum)WiO°, 



Vine ( Vitis vinifera) 2878°. 



Broad-leaved Lime (Tilia grandifolia) 3033°. 



Small-leaved Lime (Tilia par vifolia) 3274°. 



Oat (A vena satii'a) 3444°. 



White Lily (Lilium candidum) 3378°. 



Chestnut (Casianea sativa) 3660^ 



Immortelle (Uelichrysum arenarium) 3918°. 



Ling (Calluna vulgaris) 4164°. 



Trumpet-tree (Catalpa syringoefolia) 4275°. 



Blue Aster (Aster Amellus) 4874°. 



Syrian Marsh-Mallow (Hibiscus Syriacus) 4986°. 



Meadow SafTron (Colchicum autumnale) 5024°. 



Ivy (Hedera Helix) 5910°. 



Constants for the Ripening of Fruit. 



Wild Strawberry (Fragaria vcsca) 2071°. 

 Gean (Prunus avium) 2778°. 

 Mezereon (Daphne Mezereum) 2935°. 

 Red Currant (Ribes rubrum) 3069°. 

 Gooseberry (Ribes Grossularia) 3596°. 

 Alpine Woodbine (Lonicera alpigena) 4164°. 

 Mount;iin Ash (Sorbus aucuparia) 4339°. 

 Barley (Hordeum vulgare) 4403°. 

 Apricot (Prunus Armeniaca) 4435°. 

 Apjile (Pirus Halus) 4730°. 



Barberry (Berberis vulgaris) 4765°. 



Carthusian Pink (Dianthus Cart/nisianorum.)4QT4°. 



Elder (Sambucus nigra) 4913°. 



Pe.-ir (Pirus communis) 5024°. 



Cornel (Cornus m.as) 5416°. 



Plum (Pru)ius domestica) 5780°. 



Vine ( Vitis vinifera) 5780°. 



Peach (Persica vulgaris) 6004°. 



Horse Chestnut (JEsculus Hippocastanum) 6034°. 



Oak (Quercus pedunculata) 6236°. 



