612 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1908. 



of his account need be given. It was explained that each nest was 

 composed of a single plant or tuft (frond) of the gulf weed {Sa?'- 

 gassum baccifet^u/m), and by commencing with the slenderest outer 

 branchlets and peeling all successively off, an entire frond could be 

 spread out. A frond, then, of gulf weed, it was assumed, was selected 

 by a Pterophryne with ripe eggs and she proceeded to make a recep- 

 tacle or nest for the eggs. She places herself in the center or starting 

 point of a tuft and connects together the basal branches, placing some 

 eggs and with them a glutinous thread which binds together the 

 next dividing branches, and so on until she brings together the ter- 

 minal branchlets and forms a spheroidal mass or nest, as large as a 

 couple of fists or perhaps a man's head. All the time she unloads 

 her eggs in the mass and in so doing improvises the thread needed 

 for binding the mass together. Indeed, Vaillant observes, the bind- 

 ing material which this fish uses in her labor, in all jDrobability, is 

 of the same nature as the agglutinative substances which many other 

 fishes employ to fix their eggs and which they secrete at the moment 

 of spawning. Thej^ are in the form of filaments of extreme tenuity 

 (" 0™°^, 010 a O™"*, 015 "), very regularly calibrated save at the points 

 of adherence to the eggs, where there is generally found a kind of 

 expansion. These filaments are brought together in greater or less 

 number to form cords of which the diameter may sometimes exceed 

 half a millimeter. 



Another long account of " nests " and eggs attributed to the sar- 

 gasso fish was published by K. Mobius in 1894." The mass was 

 obtained in midocean (4° 45' N. lat., 30° 40' W. long.), and was 

 sacciform, 50 centimeters deep and with a diameter of 40 cm.; it 

 had two openings, one 25 cm. wide and another 10 cm. wide. The 

 eggs were distributed through the mass, and it Avas estimated that 

 the aggregate of 1,130,574 was distributed therein. 



The eggs, according to Mobius, had an average diameter of more 

 than a millimeter and a half (1.67 mm.), and at both poles were de- 

 veloped bunches of more or less elongated filamentary processes; 

 in each cluster are from 15 to 30 filaments, 7 to 12 thicker and 12 to 

 21 thinner. Some of these filaments were as much as half an inch 

 (12 mm.) long; all were very slender, some thicker (lC-24 fi) with 

 wider conical bases of insertion (32-64 /a thick), others thinner (8- 

 10 fx) with correspondingly reduced bases (32-40 /x). It is by means 

 of these tendril-like filaments that the eggs are kept in place in the 

 nest. 



Mobius has especially insisted that for the eggs thus provided for, 

 the female is responsible and not, as in the case of the Stickleback, 



" tJber Eiernester pelagischer Fische ans dem mittelatlautischen Ocean. SB. 

 K. Preuss. Akad. Wiss., Berlin, 6. Dec. 1894, L. (pp. 1203-1210). 



