CHROMOSOME COMPLEX OF SPERMATOCYTES. 327 



Within the well defined genus Hcspcrotcttix occur the three 

 clearly marked species, pratensis, spcciosus and viridis and the 

 germ cells of these exhibit the same grouping of chromosomes 

 at least of the ones most clearly distinguishable. Very prob- 

 ably when the complex is more thoroughly studied and under- 

 stood there may be detected variations that are now obscure. 

 Taking the case of the hexad multiple chromosome as being the 

 clearest element to distinguish in the present^state of our knowl- 

 edge, it is found that in viridis (?) the tetrad portion shows a 

 pronounced difference in size from that of the corresponding 

 element in speciosits. Along with this are associated differences 

 in the form and size of the spindle, etc. - - a condition that may 

 accompany, or be caused by, differences in the chromosomes. 

 These peculiarities are connected with the exhibition of the body 

 characters that are utilized for the purpose of classification. 

 Whether these particular structural peculiarities are of the first 

 importance or otherwise we have no way of determining, and 

 this may delay the progress of our knowledge if there be differ- 

 ences in the power of transmission between characters of different 

 rank in functional importance. We can not, therefore, with our 

 present information, say, for example, that the variations of the 

 structures mentioned are the cause of the difference in the size 

 and proportion of the body in the two species, or whether they 

 have to do with the surface markings on the exoskeleton. But 

 when we know the full history of each chromosome in the com- 

 plex and can follow its variations in all the species of the genus 

 and can know how it differs from others in nearly related genera, 

 then we may be able to associate a particular chromosome with 

 a definite group of characters. 



However, in these minutiae we shall have to await further and 

 much broader knowledge, and for the present turn our attention 

 to the more general questions that have centered around the 

 larger cytological phenomena in their relation to body char- 

 acters. It is not my intention to take up the question of the 

 form and sequence of the maturation mitoses, since I intend to 

 treat these matters /;/ cxtenso in a later paper. It will suffice to 

 say here that the enlarged views gained by more recent study 

 have tended only to confirm me in the opinions that I have 



