Hyatt.] 306 April 4, 



eontogr. Vol. 3, 1880-81, p. 29) to the well known and frequently 

 described increase of complication in the sutures which takes 

 place during growth in every individual, and then shows that the 

 earlier or goniatitic stages are abbreviated in the young of the 

 mesozoic Amnion itinae. He is thus able to compare this process 

 of the abbreviation in later species of the earlier ancestral char- 

 acters and correlate its progress with the similar progressive 

 complication, which takes place in the adult forms in time. He 

 then inquires if this progress in the sutures in adults is an acci- 

 dent, " ein reiner Zufall," or if it stands in definite or causal 

 hereditary relation to the concentration or shortening of the 

 simpler or Goniatitic stages of the sutures in the more recent 

 forms. 



We think that it would have been no injury to his thorough 

 and remarkable embryological contributions, if he had noted 

 more fully our remarks on the nautilian character of the first 

 septum in the Goniatites and Ammonites, and of the additional 

 fact that every Goniatite passed through a nautilinian stage, and 

 every Ammonite through a goniatitic stage. Dr. Branco was 

 perhaps misled by our figure (Embryol. of Cephalopods, pi. 3, 

 fig. 3) which has an accidental ventral fissure in the first septum. 

 We distinctly state on page 86, however, that this was due to 

 the "violent removal of the shell," and describe the first septum 

 as having an entire ventral saddle in both Goniatites and Ammo- 

 nites on pages 61, 64. These and other facts such as the earlier 

 inheritance of siphon al coecum in the protoconch of the Amrao- 

 noidea, which Dr. Branco erroneously rejects, are due to the law 

 of concentration and acceleration in development, or the shorten- 

 ing of the earlier stages of development in more complicated and 

 later occuring species. The same author's supposition that the 

 degenerate forms cannot be distinguished as such, but may be 

 cited as facts against this theory shows that he has not under- 

 stood the close coiled embryos of these forms, and is either not 

 acquainted with the researches of Quenstedt, or has failed to 

 consider then worthy of his attention. When an author takes 

 high ground in favor of any special method one has a right to 

 expect unusual freedom from error. Dr. Branco's method, how- 

 ever, has not enabled him to escape the usual fate of authors, 

 whether fact- worshippers or theorists. He has misinterpreted 



