ORTHOPTERAN SPERMATOGENESIS 695 



extremities in the equatorial plate; rods are pulled apart by 

 gliding along each other in the equatorial plate until separated. 

 (6) Fiber attachment is either median or subterminal. (7) 

 Anaphase chromosomes are U's or V's for median fiber attach- 

 ment, or J 's in subterminal. (8) The first spermatocyte division 

 is reductional. (9) In the second spermatocyte an equation 

 division occurs. 



e. Phasmidae 



Jordan ('08 a, '08 b) presents a study of the spermatogenesis 

 of the Phasmid, Aplopus mayeri, in which he deals at length only 

 with the accessory chromosome. This is typically Orthopteran 

 in its behavior. Additional facts having relation to maturation 

 processes are that the 35 chromosomes of the spermatogonium 

 become reduced during synapsis to 18, of which one is the acces- 

 sory chromosome, and that these undergo a prereduction. 



As a part of a comprehensive study of Phasmid structure de 

 Sinety ('01) reports the maturation phenomena in the male of 

 several species. Since his conclusions have been discussed in 

 connection with Oedipoda they will not be taken up here. 



/. Forficulidae 



Zweiger ('07) reaches the following conclusion from his study 

 of the spermatogenesis of Forficula auricularia: (1) The haploid 

 number of chromosomes, 12 or 13, is reached through a telo- 

 synapsis of the 24 or 26 chromosomes of the spermatogonium. 

 (2) Tetrads in the form of rings are produced by the folding 

 of longitudinally split bivalents joined end to end. The enclosed 

 space is interchromosomal. (3) Concentration of the prophase 

 rings results in the formation of dumb-bell shaped metaphase 

 chromosomes. (4) These are placed on the spindle so that homol- 

 ogous chromosomes lie superimposed. (5) In the metaphase 

 these are merely separated from each other. (6) Position of 

 fiber attachment is not described but it must be median. (7) 

 The anaphase chromosomes are spherical bodies. (8) By sep- 

 aration of whole spermatogonial chromosomes the first sperma- 

 tocyte mitosis becomes a reduction division. (9) In the second 



