ODOURS OF FLOWERS 93 
(&) Violet-odour : Viola mirabilis; Matthiola annua, incana, varia; Cheiranthus 
Cheiri, Hesperis matronalis, Leucojum vernum, Gentiana ciliata, Daphne Laureola, 
Nymphaea coerulea, Sarracenia purpurea ; 
(2) Cyclamen-odour : Pyrola uniflora ; 
(m) Paulownia-odour : Glycine chinensis ; 
(x) Flang-ylang-odour : Zaluzianskia lychnidea. 
The above-named flowers with odours agreeable to man all conceal their honey 
much more deeply than the flowers of the former group, so that it is only accessible 
to insects possessing a moderately long or very long proboscis. Accordingly, the 
benzoloid odours are agreeable to those insects (bees, moths, and butterflies) which 
are the most industrious floral visitors. 
4. Paraffin Odours. Among these Kerner includes odours that are peculiar 
to those acids and alcohols among hydrocarbons described as paraffins. Special 
forms of them are the valerian odour of Valeriana officinalis, montana, and saxatilis 
(due to valerianic acid); the rose-odour (due to pelargonic acid), especially character- 
istic of Rosa centifolia ; the rue-odour of Ruta graveolens (due to oil of rue); the vine- 
flower-odour (due to aenanthic acid) of Vitis vinifera, Gleditschia triacanthos, and 
G. sinensis; the linden-odour of Tilia alba, parvifolia, and others; and Aesculus 
macrostachya ; the nightshade-odour of Datura Stramonium, and others; Mandragora, 
Petunia, and Paeonia; the elder-odour of Sambucus nigra and Orchis pallens; and 
the goat-odour (due to caproic acid) of Himantoglossum hircinum and Orchis pallens. 
Kerner’s ‘ paraffinoid’ odours seem to me to constitute the least consistent 
group. The disagreeable odour of rue, of Datura, and of valerian is in such 
sharp contrast to the delightful fragrance of the vine and rose that I cannot regard 
the paraffinoid odours as a natural group, in spite of their chemical affinity. More- 
over, the circle of visitors of the flowers concerned is heterogeneous, including flies 
and bees, insects which respectively possess the shortest and the longest proboscides 
and are the idlest and busiest guests. 
Kerner is doubtful whether the odour of honey should be classified here, for it is 
not due, as formerly supposed, to myricil alcohol (a paraffin derivative). The odour 
of honey is the commonest of all the odours of flowers. It occurs, according to 
Kerner, in many natural orders, e.g. in the flowers of the sloe (Prunus spinosa), 
apricot (P. Armeniaca), cherry (P. avium), almond (Amygdalus communis), Hermi- 
nium monorchis, Prunus Padus (combined with an aminoid odour, according to my 
experience), Galium cruciata, vernum, verum (combined with odour of woodruff, in 
my opinion), Myosotis alpestris, Phlox paniculata, Asclepias, Cynanchum, Corydalis 
cava, Euphorbia Cyparissias, Salix Caprea, daphnoides, and others ; Cirsium arvense, 
Angelica officinalis, Heracleum Sphondylium, Meum Mutellina, Pimpinella magna, 
Alyssum montanum, Erysimum odoratum, Tulipa sylvestris, Allium sibiricum, 
Chamaemoly, and others; Polygonum Fagopyrum, Trifolium pratense, resupinatum, 
Lathyrus odoratus, and others. 
5. Turpenoid Odours, These are such odours as are derived from terpenes, 
i.e. ethereal oils which do not contain oxygen. These are sometimes enclosed in 
special cells within the plant-body, sometimes in stalked epidermal glands on the 
stem or leaves, more rarely on the flowers. Oil of neroli, for instance, produces 
