BOTANICAL GAZETTE. 337 



Index of host plants of the srEciES of Peronospora and Cystopus. 



Ranumculacece. — Anemone nemorosa, A. Pennsylvanica, Hepatica triloba, 7. 

 Ranunculus acris, R. bulbosus, 20. 



Fumariacece. — Dicentra Canadensis, D. Cucullaria, 22. 



< 'rueiferce. — Species varise, 9, 32. 



Violacece. — Viola tricolor, 18. 



Portulacacea. — Portulaca oleracea, 35. Claytonia Virginica, 11. 



'.'< raniacece. — ( Jeraniurn maculatum, G. Robertianum, G. Carolinianum, 4. 



Balsaminacece. — Impatiens fnlva, •"». 



Vitaeece. — Vitis sp. var., Ampelopsis quinquefolia, 1. 



Leguminosce. — Astragalus Canadensis, 21. 



Rosacea'. — Rosa Californica, 30. Potentilla Norvegica, Geurn album, G. ri- 

 vale, 10. 



Onarjracar. — Oenothera biennis, 13, 15. 



Curiirbifacece. — Sicyos angulatus, 27. 



UmbeUiferce. — Species indet. 5. 



Composites. — Ambrosia artemisiafolia, 2. 33. Eupatorium purpureum, Bidens 

 frondosa, Rudbeckia laciniata, Silphium terebinthinaceum, Helianthus- 

 strumosus, H. doronicoides, H. tuberosus, Solidago Canadensis, 2. Aster 

 Novse-Angliae, Erigeron Canadense, Solidago rigida, 6. Nabalus albus, 

 Lactuca altissima, L. Canadensis, L. sativa, Mulgedium leucophanun, 8.. 

 Artemisia biennis, 26. Tragopogon porrifolius, Parthenium integrifoli- 

 um, Cirsium arvense, 33. 



Plantaginacece. — Plantago major, 17. 



Scrophulariacea'. — Veronica alpina, 24. Linaria Canadensis, 25. Scropbularia 

 Californica, 29. 



LabiatcB. — Lophanthus scrophulariafolius, 31. 



Borraginacece. — Myosotis verna, 12. 



Convolmilarea'. — Sp. var. 33. ? 



Chenopodiacece. — Chenopodium album, Atriplex hastata, Spinacia oleracea, 15. 



Ainarantarar.- Amarantus hybridus, A. retroflexus, Acnida cannabina, 34. 



Polygonacece. — Polygonum dumetorum var. 16. 



Eupkorbiacece. — Euphorbia maculata, 23. 



Urlicaeece. — Urtica sp. ? 19. Parietaria Pennsylvanica, 28. 



GENERAL NOTES. 



Sections of Wood Arranged for Instruction in Schools, by H. Brooks, of 

 Boston, are offered to the students of botany and others interested in the 

 knowledge of our timber trees. The collection contains seventeen species of 

 woods, each in three specimens, a radial, tangential and a transverse section, 

 each 5.} by nearly 2 inches wide and, according to the character of the wood, 

 sV to isu incn thick. The three different sections of each species are mounted 

 on a neat card-board and are on both sides protected by a thin and completely 

 transparent mica plate, so that dust and use can not injure them and they can 

 be readily examined with transmitted as well as reflected light ; with a good 

 magnifying glass they show the wood structure very nicely. 



There are seventeen species of wood in each set, which is furnished in a 

 neat box, at $5.00 ; application to be made to Henry Brooks, 97 Beacon street, 

 Boston, Mass. 



The specimens are similar to those furnished by Mr. Burkart of Briinn,. 



