No. 1. — Observations on Budding in Paludicella and some other 

 Bryozoa. By C. B. Davenport.* 



Contents. 



Page 



A. Special Part. 



I. Introduction 1 



il. Budding in Paludicella ... 2 



1. Architecture of the Stock . 2 



2. Histology of the Budding 



Region 4 



3. Origin of the Polypide in 



the Terminal Bud ... 7 



4. Origin and Development of 



the Lateral Branches . . 9 



5. Development of the Body 



Wall 12 



6. Development of the Polypide 18 



7. Origin of the Muscles . . 27 



8. Formation of tiie Neck and 



Atrial Opening .... 31 



9. Development of the Com- 



munication Plate ... 32 

 10. Role of the Mesodermal 



Vacuolated Cells . . .34 



Page 



III. Budding in Marine Gymno- 



Icemata 40 



1. Arcliitecture of tlie Stock . 40 



2. Origin and Development of 



the Individual 53 



3. Regeneration of the Polypide 64 



IV. Origin of the Gemmiparous 



Tissue in Phylactolaeniata . 66 



B. General Considerations. 



I. Laws of Budding 



II. 



71 



Relation of the Observations on 

 Budding in Bryozoa to the 

 Germ Layer Theory ... 88 



III. On some Characteristics of 



Gemmiparous Tissue . . 98 



IV. Relationships of Endoprocta 



and Ectoprocta 102 



Summary 106 



Literature cited 109 



A. SPECIAL PART. 

 I. Introduction. 



The somewhat heterogeneous studies here brought together have been 

 prosecuted at different times and in different places, as opportunity for 

 getting light on the problem of non-sexual reproduction as exhibited in 

 the group of Bryozoa has presented itself. 



While studies on the fresh water species were pursued chiefly here at 

 Cambridge, those on marine Bryozoa were made while occupying one of 

 the tables of the Museum at the United States Fish Commission Labora- 



1 Contributions from the Zoological Laboratory of the Museum of Comparative 

 Zoology, under the direction of E. L. Mark, No. XXVIII. 



VOL XXII. — NO. 1. 1 



