98 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
different shape may behave differently in their orientation on the 
maturation spindles. McClung has recently gone over this matter 
in a very painstaking way, and I can agree with his conclusion that, 
in general, the chromosomes with the spindle-fiber attachment termi- 
nal, that is, rod-shaped chromosomes, are oriented in the first matura- 
tion spindle so as to produce an equational division, while those which 
have the spindle-fiber attachment non-terminal, that is, at the apex 
of V-shaped chromosomes, become oriented so as to bring about a 
reduction at the first division. This genéral rule is of course violated 
when the pairs of rods are of unequal length, which usually (Baum- 
gartner, 711; Payne, ’12; Carothers, ’13; Robertson, ’15), but not 
always (Ci, described in this paper), divide reductionally in the first 
division. Davis (’08) sought to establish the behavior of the V- 
shaped chromosomes of Stenobothrus as the type for the Orthoptera in 
general. He correctly described the behavior of these chromosomes 
in the maturations, but fell into error by attempting to make the rod- 
shaped chromosomes conform to the same type of behavior. He also 
failed to recognize parasynapsis. I have recently made a study of 
the conditions in Stenobothrus and may say that I found parasynapsis 
for both forms of chromosomes, and that the V-shaped chromosomes 
divide reductionally in the first maturation mitosis, as Davis de- 
scribed, but that the rod-shaped chromosomes divide equationally 
in the first division, as I found that they did in Phrynotettix. 
b. Recent Work on Synapsis. 
That parasynapsis has a wide occurrence, is evident from a glance 
at the cytological literature, especially within recent years. Grégoire 
in his two admirable monographs (’05, 710) has reviewed most of the 
previous literature bearing on the subject of the behavior of the 
chromosomes in maturation, and has endeavored to find a common 
type of behavior for both plants and animals. He says (’10, p. 384): 
“Dans un bon nombre d’objets animaux et végétaux, les cinéses de 
maturation s’accomplissent suivant le type d’une préréduction hétéro- 
homéotypique préparée par une pseudo-réduction prophasique par 
parasyndése ou zygoténie.” In this “hétérohoméotypique”’ scheme, 
however, Grégoire has failed to distinguish the difference in behavior 
between the chromosomes with terminal and those with non-terminal 
spindle-fiber attachment. Since the publication of Grégoire’s later 
monograph, a considerable number of investigators have reported 
the existence of parasynapsis. 
