148 
IOWA ACADEMY OF SCIENCE 
paugh 11 , Coville 18 , Peck 19 , J. U. & C. G. Lloyd 30 , Stebler & 
Schroeter 31 , Schaffner 3 3 , R. Schimpfky 33 , and Winslow 34 . 
In the sequence given in the following list we have followed the 
Engler and Prantl die Natuerlichen Pflanzen Familien. 
EUTHALLOPHYTA. Schizophyta. 
SCHIZOMYCETES. 
Bacteria produce disease in two ways: — First , as parasites when they de- 
rive their nourishment from the living* animal; in this case they may cause 
embolism as in the case of Bacillus anthracis or toxaemia as in diphtheria 
bacillus; or they may produce within the body products that are poisonous. 
The tetanus bacillus though parasitic produces powerful poisons that when 
injected even in minute doses cause a fatal termination, producing all the 
symptoms found in animals having the disease. Second, many saprophytic 
bacteria produce poisonous substances, especially such as occur in putrid flesh, 
fish, and other decaying substances. The list of such organism is a long one 
and cannot be given in this conection. 
SCHIZOPHYCEAE. oscillatoriaceae. 
1. Oscillaria. 
Several species in the state, probably somewhat injurious. 
Nostocacae. 
2. Nostoc caeruleum, Lyngb. 
3. N. muscorum, Ag. 
4. N. commune, Vauch. 
Dr. J. C. Arthur some years ago thought that one of the common blue- 
green algae, a species of nostoc, found in lakes in Northern Iowa and South- 
ern Minnesota, was poisonous. Its poisonous nature was not conclusively 
demonstrated. These algae have been suspected in other parts of the world. 
Mr. George Francisi calls attention to the Nodularia spumigena occurring in 
a fresh water lake in Australia. Thirty ounces of a scum fed to sheep pro- 
duced death. It is also poisonous to horses, dogs and pigs. Many of the 
algae of this group produce very disagreeable odors when decomposition occurs, 
and this plant is no exception to the rule. A few of these algae may be 
mentioned. 
17. Medicinal Plants, 1:99, pi. 99. 2:100-180, pi. 180. 
18. Poisonous Mushrooms, Cir. Div. Bot. 13:24. 
19. Edible and Poisonous Fungi of New York, Ann. Rep. State Bot. of State of N. Y. 
1896:105-248, pi. 43. Rep. State N. Y. Mus. Nat. Hist. 48. 
20. Drugs and Medicines of N. Amer., Ranunculaceae 1:304, pi. 24, f. 105. 
21. Beitrage zur Kenntniss der Matten und Weiden der Schweiz. Landw. Jahrb. d. 
Schweiz 5:141-225, pi. 20, f. 4. 
22. Poisonous and other Injurious Plants of Ohio, Ohio Naturalist 4:16, 32, 69. 
23. Deutschlands Wichtigste Giftgewachse in Wort und Bild nebst einerabh andlung 
ueber Pflanzengifte, pi. 27. 
24. Veterinary Materia Medica and Therapeutics, 775. 
1. Nature 18:11. 
