464 WILLIAM M. GOLDSMITH 
13. SUMMARY 
1. The behavior of the chromosomes of the beetles has been 
divided into three types; each is represented by a typical fertil- 
ization formula. 
2. The early spermatogonia possess neither perceptible cell 
walls nor syncytial membranes. However, the latter soon forms 
and divides the testicular tubule into definite syncytia. All 
the cells in each syncytium are in exactly the same stage of devel- 
opment. This synchronism is broken, however, in the late 
maturation divisions after the cell walls become apparent. 
These observations would suggest that the contents of each 
syncytium, rather than the cell itself, constitute a unit of cellular 
activity. The early oogonia possess very definite cell walls, 
there being no indication of a syncytium or a cyst. 
3. The spermatogonial number of chromosomes for each of 
the five species studied is twenty-two. The oogonial and the 
female somatic number is twenty-four each. Two distinct 
types of spermatogonia were found. The late spermatogonial 
cells are much smaller and stain more intensely than do those of 
the earlier divisions. The chromosomes of the late divisions are 
crowded and very difficult to figure. 
4. Definite pairs of chromosomes are readily recognized in 
every clear spermatogonial, oogonial, and somatic metaphase 
plate. 
5. The eleven first spermatocyte chromosomes are very 
irregular in shape and especially difficult to figure. Autosomes 
in the form of complete and incomplete V’s of various sizes, 
rings, hooks, and rods were figured from side views of the spindles. 
The secondary spermatocyte numbers of chromosomes are ten 
and twelve. They are much more uniform than those of the 
first division. 
6. The ‘sex-chromosome’ appears on the first spermatocyte 
spindle as a double body, the two elements (X, x) of which are 
very unequal in size and loosely united. 
These elements neither divide nor separate in the first divi- 
sion, but pass to one pole in advance of the autosomes, giving 
