OF А CAMBRIDGESHIRE WOODLAND. 385 
PLATE 15, 
Fig. 3. Spirea Ulmaria- Deschampsia cespitosa Society. A wet part with Juncus effusus 
abundant and Cnicus palustris. 
4. Fragaria vesca Society. Showing mixed nature: Habenaria virescens, Primula 
elatior, Spirea Ulmaria, Cnicus palustris, Scilla nonscripta, and Rubus sp. 
PLATE 16. 
Fig, 5. Mercurialis perennis Society. Mercurialis dominant with Scilla, and Rubus cestus. 
6. Pteris aquilina- Holeus mollis Society. Vernal aspect. 
PLATE 17. 
Fig. 7. Pteris aquilina-Holeus mollis Society. Early summer aspect showing absence of 
shrubs. 
к, The same. Late summer aspect showing Betula. 
SUPPLEMENT. 
Sıxce the above was printed the following analyses of soils from Gamlingay 
Wood, carried out at the laboratories of the Rothamsted Experimental 
Station, have come to hand. 
SOIL А. 
Soil from Spiræa Ulmaria Society in deep shade :— 
A,. Top inch soil blackish brown. 
Ау. 2-6 inches darkish coloured with Spiræa rhizomes. 
A; 7-22 „ lightyellow clay or loam. Roots to 14 ins. 
Ay. 22- „clay with numerous chalky lumps. 
| | 
ГА, А, \, А 
I—— ПО О НН И — 
Stones over 3mm, ............ | Nil 0:45 | 0:60 8-1 | 
Fine gravel above 1 mm. ...... | 0:53 | 0:69 | 0:71 2:26 | 
Coarse sand 1-02 mm. ........ | 25°76 22:53 | 1491 10:08 
Fine sand 0:2-0:04 mn. ........ | 3:92 14:91 12:26 8:26 | 
Silt 0:04-0-01 mm. ........ | 14:68 | 18:60 10:30 7:59 | 
Fine silt 0'01-0:005 mm. ...... 8:59 | 842 6:62 15:96 | 
» „ 0005-0002 mm. ...... 8:07 | 5:79 | 4:57 24-91 
Clay below 0:002 шш........... 9:21 | 13771 | 8551 0:02 
Loss on sol. in N/5 HCl........ 457 | 4:50 | 1:42 10:50 
Loss on ignition of dry sample .. 12:52 7:74 | 7:36 22:07 
Moisture ................. ... 3°38 3°26 | 5:33 | 1:59 
Potash (K,O) .............. .. ] not 0:48 || not | 0:756 
Phosphoric acid (P,O;) ........ | determined. 0:074 J] determined. 0:119 
| Lime (CaCo,) ................ | 0:12 004 0:3 19:50 
Humus ,..... ОЧ | 3°98 3 378 9:38 
teaction to Litmus........ .... neutral. very slightly alkaline. distinctly 
| | acid. alkaline. 
