JOURNAL ^^'s' 



OF THE 



]OFtD JBopk ^nj^omologiral ^oriFJ^g. 



Vol. XXVI. MARCH, 1918. No. i 



THE AEROBIC NATURE OF INSECT TISSUE. 



By R. W. Glasf.r, 

 Forest Hills, Mass. 



It is. a well-known fact that insect tissue is aerobic, /. c, tubes 

 called trachea; ramify the entire body and supply air directly to the 

 cells. There is no medium, like the mammalian erythrocytes, which 

 transfers the oxygen from the lungs to the tissues. 



During the course of some work on the cultivation of insect blood 

 cells in vitro. I made some observations that clearly showed insect 

 tissue to be dependent upon direct air. Since the method could be 

 very nicely used in entomological class demonstration work, I thought 

 it well to present the observations. The method for preparing tissue- 

 culture slides is familiar to all biologists, so I will not dwell on very 

 many of the technical details.^ Suffice it to say, that I used depres- 

 sion slides with thin No. o cover slips so that I could work effectively 

 with the oil immersion lens. Both army worm (Cirphis nnipuncta) 

 and gipsy moth caterpillar {Porthctria dispar) blood was found suit- 

 able for the experiments. 



All work must be done under sterile conditions. The animals to 

 be operated upon are held in one hand and bent back so that the ven- 

 tral side can be washed off with alcohol. When this evaporates, the 

 tip of a proleg is then quickly cut oft' with sterile sc'ssors and the drop 



1 Those interested in the cultivation of insect tissue are referred to: R. 

 ^^^ Glaser, " The Growth of Insect Blood Cells i>i vitro." Psyche, Vol. 

 XXIV, Xo. I, 1917. 



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