1907] CURRENT LITERATURE 69 
apparently with some surprise, that the morphology of Utricularia shoots can be 
best understood by considering the leaf and the axis homologous and equivalent 
Structures—a point of view perhaps not so novel to others. Various forms, 
dependent on habitat, are described in the six recognized species. The so-called 
thizoids, really modified shoots, arising from the base of the inflorescence, are 
partly anchoring and partly nutritive organs. Aerial shoots from water forms 
assist in gaseous exchange. 
The formation and behavior of turions (special buds which become detached) 
is examined in a considerable range of water plants (E/odea canadensis, Stratiotes 
aloides, Hydrilla verticillata, Myriophyllum verticillatum, Caiotets (6 spp.), 
Aldrovandia vesiculosa, Caldesia parnassifolia, Potamogeton (7 spp.), and Hydro- 
charis morsus-ranae), and the structures are figured. e formation of these 
autumn, but usually they hibernate in the water. Some withstand freezing in 
ice or mud; most are killed by it. As reproductive and hibernating structures 
the turions replace seeds largely, since the habitat of water plants is unfavorable 
to seed-form 
egeneration phenomena examined in Utricularia were referred to ‘“‘corre- 
lation, . the accumulation of plastic material at certain points causing the New- 
ung, 
Ceratophyllum, which has been widely believed to be a free swimming plant, 
18 shown to be originally anchored by “rhizoids” (peculiarly modified shoots 
6-25°™ long), which are also permeable to food materials. 
New forms are described and the general results of the study are applied to 
the taxonomy of the plants. 
Want of an index in both volumes, beyond mere names of plants, makes 
the facts gathered difficult of access. When will authors learn that they owe to 
themselves, if not to other users of their work, the drudgery of index making ?— 
C_R.B 
MINOR NOTICES 
Contributions of U. S. National Museum.—The current issue of this series 
contains the fifth paper by Roses under the title “Studies of Mexican and Cen- 
tral American plants.” It also represents the fifth journey of Dr. Rose to Mexico, 
which has enabled him to write with a large field experience. The numerous 
Plates, some of them reproductions of photographs, bring the plants vividly to 
€ eye. Four new genera are described, as follows: Calibanus (Liliaceae), 
Sphinctos permum (Viciaceae), Pseudoxalis Salome Escontria (Cactaceae). 
The four following genera have been reesta : Beaucarnia (Liliaceae), 
Odonia (Vidlaceke), Biophytum (Oxalidaceae), * Terebinthus (Balsameaceae). 
5 RosE, J. N., Studies of Mexican and Central American plants. No. 5. Con- 
trib. U. S. Nat. Herb. 10: 79-132. pls. 16-43. 1906. 
