ESTIMATION OF THE HEAT NECESSARY TO GROWTH. 



559 



add together the daily maxima of sun-temperatures from the first of January 

 until the event in question takes place. 



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

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



CONSTANTS FOR THE ISSUE OF THE FOLIAGE-LEAVES FROM THE BUDS. 



Gooseberry (Ribes Grossularia) 478. 

 Hazel (Corylus Avellana) 1061. 

 Beech (Fagus silvatica) 1439. 



Plane (Platanus acerifolia) 1503. 

 Walnut (Juglans regia) 1584. 



CONSTANTS FOR THE OPENING OF THE FIRST FLOWERS. 



Hazel (Corylus Avellana) 226. 



Mezereon (Daphne Mezereum) 303. 



Snowdrop (Oalanthus nivalis) 311. 



Sweet Violet ( Viola odorata) 576. 



Cornel (Cornus mas) 576. 



Apricot (Prunus Armeniaca) 843. 



Corydalis (Corydalis cava) 863. 



Violet Willow (Salix Daphnoides) 968. 



Cowslip (Primula veris) 968. 



Norway Maple ( Acer platanoides) 1100. 



Peach (Persica vulgaris) 1100. 



Gooseberry (Ribes Grossularia) 1138. 



Almond (Amygdalus communis) 1196. 



Gean (Prunus avium) 1265. 



Sloe (Prunus spinosa) 1265. 



Pear (Pirus communis) 1304. 



Bird Cherry (Prunus Padus) 1325. 



Apple (Pirus Mains) 1423. 



Plum (Prunus domestica) 1423. 



Alpine Woodbine (Lonicera alpigena) 1458. 



Oak (Quercus pedunculata) 1556. 



Lilac (Syringa vulgaris) 1556. 



Walnut (Juglans regia) 1584. 



Barberry (Berberis vulgaris) 1615. 



Poet's Narcissus (Narcissus poeticus) 1615. 



Hawthorn (Cratcegus Oxyacantha) 1649. 



Lily of the Valley (Convallaria majalis) 1649. 



Horse Chestnut (JEsculus Hippocastanum) 1708 



Peony (Pceonia ojjicinalis) 1818. 



Laburnum (Cytisus Laburnum) 1818. 



Mountain Ash (Sorbus aucuparia) 1844. 



Norway Spruce (Abies excelsa) 1904. 



Plane (Platanus acerifolia) 2115. 



Elder (Sambucus nigra) 2313. 



Deadly Nightshade (Atropa Belladonna) 2346. 



Acacia (Robinia Pseudacacia) 2404. 



Scotch Pine (Pinus sylvestris) 2404. 



White Water Lily (Nymphcea alba) 2506. 



Arnica montana 2538. 



Tulip Tree (Liriodendron tulipifera) 2538. 



Rosa centifolia 2538. 



Fox-glove (Digitalis purpurea) 2640. 



Carthusian T?mk(J)iantkus Carthusianorum) 2640, 



Vine ( Vitis vinifera) 2878. 



Broad-leaved Lime (Tilia grandifolia) 3033. 



Small-leaved Lime (Tilia parvifolia) 3274. 



Oat (Arena sativa) 3444. 



White Lily (Lilium candidum) 3378. 



Chestnut (Caxtanea sativa) 3660. 



Immortelle (Helichrysum arenarium) 3918. 



Ling (Calluna vulgaris) 4164. 



Trumpet-tree (Catalpa syringcefolia) 4275. 



Blue Aster (Aster Amettus) 4874. 



Syrian Marsh-Mallow (Hibiscus Syriacus) 4986. 



Meadow Saffron (Colchicum autumnale) 5024. 



Ivy (Hed,era Helix) 5910. 



CONSTANTS FOR THE RIPENING OF FRUIT. 



Wild Strawberry (Frag aria vesca) 2671. 

 Gean (Prunus avium) 2778. 

 Mezereon (Daphne Mezereum) 2935. 

 Red Currant (Ribes rubrum) 3069. 

 Gooseberry (Ribes Orossularia) 3596. 

 Alpine Woodbine (Lonicera alpigena) 4164 

 Mountain Ash (Sorbus aucuparia) 4339. 

 Barley (Hordeum vulgare) 4403. 

 Apricot (Prunus Armeniaca) 4435. 

 Apple (Pirus Mains) 4730. 



Barberry (Berberis vulgaris) 4765. 



Carthusian Pink (Dianthus Carthusianorum)^!^. 



Elder (Sambucus nigra) 4913. 



Pear (Pirus communis) 5024. 



Cornel (Cornus mas) 5416. 



Plum (Prunus domestica) 5780. 



Vine (Vitis vinifera) 5780. 



Peach (Persica vulgaris) 6004. 



Horse Chestnut (^Esculus Hippocastanum) 6034. 



Oak (Quercus pedunculata) 6236. 



