DISEASES OF PLANTS. 145 



reports are given on about (30 of the more common weeds, among which 

 are many usually found in lists of our worst weeds. 



Noxious weeds, E. S. Goff ( fi'isconsin Sta. Bal. 39, pp. 3S,figs. 19). — Popular illus- 

 trated descriptive notes, together witli geueral aud specific hiuts for their suppres- 

 siou, are given by the author on the most troublesome weeds of his State, as follows : 

 Canada thistle {Cniciis arreusifi), burdock {Arctium lappa), oxeye daisy {Chrysanthe- 

 mum leiicanthemnm), snapdragon or toadflax {Linaria vnUjaris), cocklebur {Xanthiuni 

 strumarium), sow thistle {Sonvhitu arcensis), wild mustard {IJrassioa sinapistrum), 

 sonr dock. {Rmnex crispns), wild parsnip {I'asiinacu satica), sweet clov et {Melilotus 

 alba), and the Russian thistle {SaLiuH kali tratjus). 



The acts of the State legislature relating to the destruction of noxious weeds 

 are also quoted. 



False star thistle (Kentrophyllum lanatum), J. II. Maiden {.igl. Gaz. N. S. 

 W., 5 {1S94), No. 5, pp. 20S-300, jUj. 1). — Description aud methods of exterminat- 

 ing this Australiau weed. 



DISEASES OF PLANTS. 

 Cotton-boll rot, J. M. Stedman {Alabama Sta. Bui. .55, pp. 12, pi. 1). 



Synopsis. — The author describes a new disease of cotton due to a S])ecies of bacillus 

 which is ligured aud described. It is accompanied by several saprophytic 

 fungi, and two species of beetles. The attack begins within the bolls, aud is only 

 manifest after the liut aud seed have decayed. Uurniug all diseased bolls is 

 the treatment advised. 



In 1893 the author had his attention called to what proved to be a 

 new bacterial disease of cotton bolls. Two si)ecies of beetles, or their 

 larvie, and several sa]jrophytic fungi were found in the diseased bolls 

 which were never seen in sound ones. The author was led to make 

 pure cultures of the bacteria always found in the diseased bolls, aud was 

 enabled by inoculations to cause the disease. He considers it a new 

 species, to which he gives the name Bacillus gossypina, characterized as 

 follows: 



"Short, straight bacilli, truncate with slightly rounded corners, 1.5// long and 

 0.75// broad; usually solitary, sometimes in pairs, and occasionally in chains of 

 from 3 to 4. Stains readily with the usual anilin colors. 



"An aerobic, uouliquefying (sliglit liquefaction in old gelatin cultuies), motile 

 bacillus. Forms spores. Grows at the room temperature in the usual culture media, 

 but more rapidly at 25^ to 35° C. In gelatin tube cultures the growth in 3 days 

 gives a milky appearance, which spreads from the line of puncture of the iuoculat- 

 iug needle, until in 5 days the entire gelatin becomes milky and assumes a slight 

 jjreenish color. In agar-agar the growth on the surface appears as a smooth, semi- 

 transparent, milky layer, while the development along the line of ])uncture of the 

 inoculating needle through the agar-agar takes place as a cloudy, more or less even 

 growth, gradually becoming thinner at the periphery. 



" Inoculated into healthy cotton bolls, a disease resulting in a rotting or decaying 

 of the seed and lint is produced in from 1 to 2 weeks, which soon involves the car- 

 pels, and thus destroys the entire cotton boll." 



The disease is easily distinguished from anthracnose {Colletotrichum 

 gossipii) by the latter making its appearance as small reddish-brown 

 spots, which enlarge and become dark, gray, or pink, as the case may 



