630 PATTERNS AND PROBLEMS OF DEVELOPMENT 



tions apparently originate in the course of development and differentia- 

 tion, they are presumably reactions to some factor of developmental 

 pattern. Such a factor may be local and related to cell surfaces, as the 

 cellulose pattern evidently is in various cells, or to local tensions or pres- 

 sures in a tissue, as in connective tissue, or within the cell, as perhaps in 

 development of the mitotic figure ; or it may be associated with organismic 

 pattern, particularly if that pattern is unicellular. In a multicellular pat- 

 tern local conditions may be more effective in determining molecular or 

 micellar pattern than the general pattern of the whole, though the local 

 factors are doubtless derivatives of the general pattern. 



Most spermatozoa are certainly highly differentiated and structurized 

 unicellular organisms and contain little or nothing resembling even the 

 protoplasms of ordinary tissue cells, and still less those of embryonic cells. 

 If molecular pattern and orientation can become evident in morphological 

 pattern in any cells, it seems likely to be in spermatozoa. They are minute 

 and undergo perhaps a more extreme structural differentiation than any 

 other living cells. Many sperm heads and tails of some sperms are more 

 or less birefringent, but spherical sperm heads are apparently not bire- 

 fringent.'^ According to recent X-ray work, some sperm heads show char- 

 acteristics of fluid crystalline state. Separation of spermatozoan tails into 

 parallel fibrillae by treatment with various agents is also of interest here, 

 since it suggests a parallel orientation of elongated units (Ballowitz, 

 1890a, b; 1895). As already pointed out, however, earlier stages of sper- 

 matozoan development show only a general axiate pattern, presumably 

 involving the cell metabolism and perhaps primarily nothing more than 

 a gradient. 



Although the ectoplasm of flagellates and ciliates appears to be less 

 extremely differentiated than many spermatozoa, it, or certain parts of 

 it, certainly undergo high degrees of structurization; and this is appar- 

 ently most extreme in forms with the most extreme specific spirals or 

 other asymmetries. The frequency of spiral patterns in spermatozoa and 

 axiate Protozoa and various other organisms is of particular interest. 

 They probably represent the reaction of many protoplasms to presence 

 of an axiate pattern, but we still lack definite information as to their 

 origin and nature. Except that they are spiral, they differ widely and 

 specifically in different species. The differences do not seem to have any 

 fundamental or necessary relation to the life of the individual. Corkscrew 

 heads or spirally twisted tails may be present or absent in spermatozoa, 



"W. J. Schmidt, 1928, and his citations. 



