DEVELOPMENT OF THE BLOOD PICTURE OF THE 

 CRICKET ACHETA DOMESTICUSL. 



Развитие картины крови у Acheta domesticus L. 



/. HRDt 



(Entomological Laboratory of Czechoslovak Academy of Sciences, 

 Praha, Czechoslovakia) 



The problems relating to the study of insect hemolymph are extremely wide 

 and complicated even if we wish to pay attention to one component only. 

 There does not exist a uniform generally recognized classification of the blood 

 bodies valid on a Avide scale (for an order, resp. insects as a whole) which may 

 be due to the variety of standpoints relating to this task. 



In my work I was first interested in the morphology of hemocytes of the 

 cricket Acheta domesticus L. Having tested the most frequently used methods 

 I examined the greater part of material on dry May-Grünwald-Giemsa (Pappen- 

 heim) stained smears or on fresh preparations with the aid of phase contrast. 

 The criteria for the morphological classification were particularly: structure 

 of nucleus and cytoplasma, stainability, presence of cytoplasmic inclusions 

 and vacuolisation, size of the nucleus and cell, its shape, proportion between 

 the size of nucleus and cytoplasm. Making use of all these indications would 

 result in an extremely complicated division of hemocytes into a large number 

 of shapes hardly differing from each other. (See some classifications including 

 over 50 various forms.) The composition of all occurring forms into morpholo- 

 gically related groups enables us to form an idea on the differentiation towards 

 the well defined types representing the principal categories of this simplified 

 classification. 



The following basic types are distinguished (including some as yet incomple- 

 tely characterized categories): Nucleocytes — hemocytes "wath a compact or 

 more often roughly granulates nucleus rich of chromatin; basophile cytoplasm, 

 mostly well stainable and homogenous. Cytoplasmic border narrow till medium 

 wide. This category represents evidently the original undifferentiated shapes 

 or shapes at the beginning of differentiation. The majority of mitoses found 

 on smears occur in hemocytes belonging to this type. Transitional forms — 

 from nucleocytes to plasmatocytes; characterized by a granulous cytoplasmic 

 structvire. Transitional forms to other hemocyte types bear signs of transi- 

 tion mostly from nucleocyte to some of the differentiated types. Plasmatocytes 

 — hemocytes mostly with a well or at least medium developed cytoplasm 



106 



