36o 
I. W. BAILEY 
Comparative Lengths of Tracheary and Meristematic Cells 
GYMNOSPERMAE 
Cambial Initials 
Tracheids 
Max. 
Mean 
Min. 
Max. 
Mean 
Min. 
I. GiNKGOALES 
I. Ginkgoaceae 
^ Ginkgo biloba L 
3-0 
2.2 
1.4 
2.9 
2.2 
1.4 
II. CONIFERAE 
2. Taxaceae 
1.6 
I.I 
0.8 
1.7 
1-3 
0.8 
3. Pinaceae 
(a) Abieteae 
Pinus Strobus L 
4.0 
3-2 
2.3 
4.6 
3.4 
2.2 
Picea Abies (L.) Karst 
4.2 
3-3 
2.4 
4.2 
3.6 
2.8 
Larix decidua Mill 
4.0 
2.5 
54 
4.2 
2.7 
^ Pseudotsuga taxifolia (Lamb.) Britton. 
1.6 
1.2 
0.7 
1.8 
1.2 
0.9 
1-5 
I.I 
0.7 
1.8 
1.2 
1.0 
6 Cedrus libani Barrel 
2.6 
2.0 
1.2 
2.7 
2.1 
1-3 
6 Tsuga canadensis (L.) Carr 
1.8 
1.4 
0.9 
2.1 
1.5 
I.I 
(b) Taxodieae 
6 Sciadopitys verticillata Sieb. and Zucc. 
1.6 
1.2 
0.7 
1.6 
1-3 
1.0 
^ Sequoia gigantea Lindl. and Gord 
4.5 
3-7 
2.5 
4-5 
3-8 
2.8 
(c) Cupresseae 
2.1 
1-5 
0.7 
2.4 
1-7 
1-3 
Juniperus virginiana L 
3-0 
2.2 
I.O 
3-0 
2.3 
1.4 
ANGI0SPERMAE-DIC0TYLED0NEAE7 
Vessel-segments 
Cambial Initials 
Fiber Trac 
leids 
Max. 
Mean 
Min, 
Max. 
Mean 
Min. 
Max. 
Mean 
Min. 
A. Archichlamydeae 
I. 
Salicales 
I. Salicaceae 
II. 
0.70 
0.50 
0.19 
0.66 
0.49 
0.35 
1. 19 
0.90 
0.61 
Juglandales 
2. Juglandaceae 
Carya glabra Sweet. . . . 
0.63 
0.43 
0.20 
0.70 
0.56 
0.40 
1.69 
I-I3 
0.65 
Carya ovata (Mill.) C. 
Koch 
0.55 
0.51 
0.47 
0.60 
0.52 
0.42 
1.69 
1.30 
0.96 
III. 
Fagales 
3. Betulaceae 
Alnus incana (L.) 
0.84 
0.66 
0.43 
0.72 
0.60 
0.34 
1.20 
1.89 
0.56 
Betula populifolia 
1. 17 
0.89 
0.65 
1. 16 
0.94 
0.70 
1.60 
I-3I 
0.91 
4. Fagaceae 
Quercus alba L 
0.60 
0.46 
0.36 
0.67 
0.53 
0-39 
1.42 
1. 00 
0.80 
IV. 
Urticales 
5. Ulmaceae 
Ulmus americafia L.. . . 
0.59 
0.33 
0.21 
0.47 
0.35 
0.27 
1.96 
1-53 
1. 12 
V. 
Ranales 
6. Trochodendraceae 
Euptelea polyandra 
0.97 
0.72 
0.39 
0.86 
0.63 
0.40 
1.42 
0.95 
0.59 
7. Annonaceae 
Annona reticulata L.. . . 
0.43 
0.29 
0.13 
0.39 
0.33 
0.22 
I.7I 
1.28 
0.83 
^ Material obtained from small branches or young stems. 
^ Material obtained from stems of various ages. 
