1900] Leavitt, — Relation of plants to moisture 63 
Hypnum Haldanianum Grev. (no. 322). 
Hypnum ochraceum Turn. (no. 322.11). 
Leskea polycarpa Ehrh. (no. 265). 
* Leskea nervosa (Schwaegr.) Myrin. 
Mnium sylvaticum Lindb. (no. 160). 
Plagiothecium denticulatum (L.) Br. & Sch. (no. 314). 
Plagiothecium turfaceum Lindb. ` 
Pogonatum alpinum (L.) Roehl. (no. 180.) 
Raphidostegium recurvans (Mx.) J. & S. (no. 307). 
Rhynchostegium rusciforme (Neck.) Br. & Sch. (no. 305). 
Sphagnum acutifolium (Ehrh.) Russ. & Warnst. (no. 4). 
* Sphagnum acutifoltum purpureum Warnst. 
Sphagnum acutifolium rubrum (Brid.) Warnst. 
Thuidium delicatulum (L.) Mitt. (no. 274). 
Thuidium recognitum (Hedw.) Lindb. 
* Thuidium scitum aestivale Aust. 
Webera sessilis (Schmid.) Lindb. (no. 172). 
SCALE-MOSSES. 
Geocalyx graveolens (Schrad.) Nees (no. 17). 
Plagiochila asplenioides (L.) Dum. (no. 20). 
Scapania nemorosa (L.) Dum. (no. 15). 
Trichocolea tomentella (Ehrh.) Dum. (no. 7). 
WASHINGTON, D.C. 
THE RELATION OF CERTAIN PLANTS TO ATMOSPHERIC 
MOISTURE. 
ROBERT G. LEAVITT. 
: (Concluded. ) 
Oncuips (continued). A very few figures will convey a more pre- 
cise idea of the behavior of cut roots in a humidity of from .go to .95, 
mostly nearer the higher figure. 
Species. Wt. at Time Conditions. Loss. Temperature, 
start. elapsed. Gms. 
Gms. 
Dendrobium 535 24 hrs. In lab. 095 70° + 
nobile. 
.440 46 hrs. .95 Xi hum.  .040 669—699 
Dry weight .340 : 
Burlingtonia .310 4 days S .040 o 
decora. 
Oncidium 1.10 2 days Lx .o8 « 
varicosum. 
Dry weight ET 
