1901] Andrews,— Observations on Orchid Fragrance 85 
Of course we must bear in mind that in all probability odors im- 
perceptible to the human sense of smell exist, which may possess for 
the small insect the very greatest attraction, and the tiny, unattractive 
Microstylis may be to the little gnat a perfect censer of fragrance; 
this probability does not, however, render valueless a classification of 
odors from the human standpoint. 
Our natural, primary division would distinguish the distinctively 
agreeable from those not distinctively agreeable which we may term by 
way of contrast disagreeable. Laying aside individual eccentricities 
of like and dislike it will be readily seen that all odors will fall pretty 
definitely into the one or the other class. The disagreeable I would 
subdivide into the positively disagreeable, i. e., those of the car- 
rion or other similar scent, the purpose being the attraction of flies 
by the suggestion of the presence of carrion, and the negatively dis- 
agreeable, i. e., those which may be called disagreeable from the lack 
of any agreeable quality, faint, oily, pungent smells, etc., probably 
attractive to some kind of insect, or possibly incidental or serving 
some other purpose. The agreeable I would similarly subdivide into 
those possessing the peculiar, distinctive flavor which we denominate 
perfume or true fragrance, and those characterized by a merely sweet- 
ish odor, one in no way distinct nor justifying the name perfume or 
fragrance, simply a suggestion of the presence of nectar, 
The plants, particularly the roots, of all our terrestrial orchids pos- 
sess a characteristic odor described by Mr. Baldwin (Orchids of New 
England) as “musky,” which can hardly be called pleasing except 
for the associations which it always suggests, but which, as being 
also present in the flowers of certain species like Habenaria orbiculata 
habitually fertilized by night-moths, undoubtedly plays a part in the 
attraction of nocturnal insects. 
Of the carrion odor and its relatives we have no examples in our 
orchids, though several tropical species display it in a very marked 
degree. 
As negatively disagreeable I would mention Cypripedium pubes- 
cns whose * heavy, oily odor" noted by Burroughs is well known 
and furnishes an easy mark of distinction between it and the closely 
related C. parviflorum. One may sometimes detect an unpleasant, 
penetrating odor in C. acaule. Here belongs Goodyera repens var. 
ophioides which exhales a characteristic, pungent odor wholly differ- 
ent from that of G. tesselata. 
bd ci 
