Bacterial Disease of the Squash-hug. 379 



{Psilura monachalj.) und Versuchsergebnisse liber den 

 Gebrauchswerth einiger Mittel zur Vertilgung der 

 Raupe. Mitth. ans dem forstlicheu Versuchswesen Oes- 

 terreichs. Der ganzen Folge, Heft XYI. Wien, 1893. 

 Walker, Philip. — Grasseiie of the Silkworm. Insect 

 Life, Yol. 3, Nos. 11 and 12, Aug., 1891, p. 445. 



EXPLANATION OF PLATES. 



Plate XXVII. 



Fig, 1. Bacillus entomotoxicon from the blood of a dis- 

 eased squash-bug. Zeiss V12 liom. imm., oc. 4, tube 

 length 205 ram. 



Fig. 2. Distribution of bacteria in the hypodermis and 

 fatty bodies of a squash-bug at the time of death: c, 

 cuticle; A, hypodermis; m, basal membrane; «, adipose 

 tissue much degenerated. Zeiss E, oc. 2, tube length 

 155 mm. 



Fig. 3. Distribution of bacteria in the blood and tis- 

 sues of a squash-bug an hour or more before death: h, 

 hypodermis: m, basal membrane; p. c, extension of 

 perivisceral cavity; a,, adipose tissue. Zeiss E. oc. 2, tube 

 length 155 mm. 



Fig. 4. Longitudinal section of the dorsal vessel, or 

 heart, of a squash-bug slightly sick, showing distribu- 

 tion of bacteria in the blood. 



Plate XXYITI. 



Fig. 1. Growth of the Bacillus entomotoxicon on nu- 

 trient agar containing a small amount of squash-leaf 

 decoction. 



* All figures were drawn with the aid of a Zeiss camera lucida. 



