Rate of carbon monoxide production 0. 08 mm 3 /hr 



0.31 "r 3.87 = 



(mm 3 ) (hours) Approximately = 0.07 mm 3 /hr 



STPD 



Weight of pneumatophore: 1. 2 mg 



Final rate of CO production (see below): 



0.08 -1.2= 0.07 mm 3 /mg/hr 



(mm 3 ) (mg) Approximately = 0. 06 mm 3 /mg/hr 



STPD 



Note Regarding Rate of CO Production 



Experiments designed to determine the rate of CO 

 production by Physalia, the Portuguese man-of-war, have 

 been conducted by Wittenberg 16 and by Larimer and Ashby. 9 

 The former obtained values of 5 to 20 ^1/hr/gas gland for 

 carbon monoxide produced, while the latter determined a 

 range of 7. 5 to 120 jul/hr/ animal. While these values appear 

 superficially high compared to the observations reported 

 here, a direct comparison is not possible since neither 

 dimensional measurements suitable for comparison, nor 

 weights, were given by those authors. 



However, in more recent work Hahn and Copeland, 

 while testing the effects of aminopterin, a folic acid inhibitor, 

 upon the carbon monoxide secreting capabilities of the ex- 

 cised gas gland of Physalta, found their control specimens, 

 when incubated at 22 °C with L-serine added as a substrate, 

 produced CO at rates ranging from 0. 280 /il/mg/hr to 

 1. 075 jil/mg/hr. My single figure for rate of CO production 

 incorporates the weight of the entire nanomian float and is, 

 therefore, not readily comparable to the above figures. 

 However, a series of dissections performed previously 

 for other purposes disclosed the weight of the goblet-shaped 

 nanomian gas gland to be in the range of 3 to 17 percent of 

 the total float weight after removal of all attached stolon; 

 that is, about 0.1 to 0„ 6 mg in floats weighing 3. to 4. 3 mg. 

 When the value reported here is regarded as representing 



46 



