Development stages of Hemidactylium scutatum 



Schlegel 



Fig. I Medullary folds well formed but nowhere approximated. 

 The earliest stage of development observed in group of eggs taken 

 May 14th. 



Fig. 2 Embryo defined on the yolk. Union of medullary folds 

 marked by median depressed line. Same date as specimen in 

 figure I but much more advanced in development. 



Fig. 3 Segregation of tissue giving indication of position, form 

 and extent of head, gill and body regions. May i6th. 



Fig. 4 Limits of head well defined; gill region with large growth 

 of tissue preliminary to actual development of gill and arm buds. 

 Embryo folded upon itself. May 19th. 



Fig. 5 Eyes highly pigmented; gill region much thickened and 

 expanded laterally. Three primary divisions of body — head, trunk 

 and tail recognizable. May 21st. 



Fig. 6 Embryo slightly more advanced than that in figure 5. 

 Tail distinct from trunk and constriction back of gill region more 

 pronounced. Reduction of yo^k mass evident in this and two 

 preceding stages. May 25th. 



